| Academy Hall | Rocky Hill | Building | 1977 |
| Aetna Diner | Hartford | Building | 2021 |
| Allen Place-Lincoln Street Historic District | Hartford | District | 2003 |
| Allen's Cider Mill | Granby | Building | 1992 |
| Allyn, Capt. Benjamin, II, House | Windsor | Building | 1979 |
| Ambassador Apartments | Hartford | Building | 2008 |
| Andrews, Luman, House | Southington | Building | 1989 |
| Ann Street Historic District | Hartford | District | 1983 |
| Apartment at 49-51 Spring Street | Hartford | Building | 1983 |
| Armsmear NHL | Hartford | Building | 1966 |
| Asylum Avenue District | Hartford | District | 1979 |
| Atwater Manufacturing Company | Southington | Building | 1988 |
| Austin, A. Everett, House NHL | Hartford | Building | 1994 |
| Avon Congregational Church | Avon | Building | 1972 |
| B.P.O. Elks Lodge | Hartford | Building | 1984 |
| Babb's Beach | Suffield | Building | 2006 |
| Barber, Giles, House | Windsor | Building | 1988 |
| Barbour, Lucius, House | Hartford | Building | 1979 |
| Barlow, Boce W., Jr., House | Hartford | Building | 1994 |
| Barnard, Henry, House NHL | Hartford | Building | 1966 |
| Barnes, Selah, House | Southington | Building | 1989 |
| Barnes-Frost House | Southington | Building | 1989 |
| Batterson Block | Hartford | Building | 1984 |
| Beach, Charles E., House | West Hartford | Building | 1990 |
| Beardsley-Mix House | West Hartford | Building | 1986 |
| Bedford-Garden Streets Historic District | Hartford | District | 2023 |
| Belden, Horace, School and Central Grammar School | Simsbury | Building | 1993 |
| Beleden House | Bristol | Building | 1982 |
| Bemont, Makens, House | East Hartford | Building | 1982 |
| Beth Hamedrash Hagodol Synagogue | Hartford | Building | 1995 |
| Bigelow-Hartford Carpet Mills | Thompsonville | Building | 1983 |
| Bigelow-Hartford Carpet Mills Historic District | Enfield | District | 1994 |
| Bingham, Clarence A., School | Bristol | Building | 2017 |
| Bissell Tavern-Bissell's Stage House | Windsor | Building | 1985 |
| Blakeslee Forging Company | Southington | Building | 1988 |
| Bloomfield Avenue Meeting House | Hartford | Building | 2024 |
| Brace, Moses-Uriah Cadwell House | West Hartford | Building | 1986 |
| Bradley, Icabod, House | Southington | Building | 1989 |
| Brewer, Selden, House | East Hartford | Building | 1979 |
| Bridge No. 455 | Suffield | Structure | 2004 |
| Bristol Girls' Club | Bristol | Building | 1987 |
| Bristol High School | Bristol | Building | 2018 |
| Broad Brook Company | East Windsor | District | 1985 |
| Broad Street Green Historic District | Windsor | District | 1999 |
| Brown Tavern | Burlington | Building | 1972 |
| Buckingham Square District | Hartford | District | 1977 |
| Buckingham Square Historic District (Boundary Increase) | Hartford | District | 1982 |
| Building at 136-138 Collins Street | Hartford | Building | 1979 |
| Building at 142 Collins Street | Hartford | Building | 1979 |
| Building at 83-85 Sigourney Street | Hartford | Building | 1979 |
| Bulkeley Bridge | Hartford | Structure | 1993 |
| Bull, Amos, House | Hartford | Building | 1968 |
| Burnham, Edward L., Farm | Manchester | Building | 1982 |
| Burritt Hotel | New Britain | Building | 1983 |
| Burwell, Ernest R., House | Bristol | Building | 1992 |
| Bushnell Park | Hartford | Site | 1970 |
| Butler, James, House | West Hartford | Building | 1986 |
| Butler, Roger, House | Wethersfield | Building | 1996 |
| Butler-McCook Homestead | Hartford | Building | 1971 |
| Buttolph-Williams House NHL | Wethersfield | Building | 1968 |
| Canton Center Historic District | Canton | District | 1997 |
| Canty, Marietta, House | Hartford | Building | 2000 |
| Capen-Clark Historic District | Hartford | District | 1982 |
| Capewell Horse Nail Company | Hartford | Building | 2000 |
| Case Brothers Historic District | Manchester | District | 2009 |
| Case, Benomi, House | Windsor | Building | 1988 |
| Cedar Hill Cemetery | Hartford | District | 1997 |
| Center Burying Yard, Old | West Hartford | Site | 2002 |
| Central Avenue-Center Cemetery Historic District | East Hartford | District | 1993 |
| Chaffee, Hezekiah, House | Windsor | Building | 1972 |
| Chapman, Taylor, House | Windsor | Building | 1988 |
| Charter Oak Bank Building | Hartford | Building | 1978 |
| Charter Oak Place | Hartford | District | 1978 |
| Charter Oak Place (Boundary Increase) | Hartford | District | 1982 |
| Cheney Brothers Historic District NHL | Manchester | District | 1978 |
| Cheney Building | Hartford | Building | 1970 |
| Chevry Lomday Mishnayes Synagogue | Hartford | Building | 1995 |
| Children's Village of the Hartford Orphan Asylum | Hartford | Building | 1982 |
| Christ Church | Hartford | Building | 1983 |
| Church of the Good Shepherd and Parish House | Hartford | Building | 1975 |
| City Hall-Monument District | New Britain | District | 1973 |
| Clark Brothers Factory No. 1 | Southington | Building | 1988 |
| Clark Brothers Factory No. 2 | Southington | Building | 1988 |
| Clark Farm Tenant House Site | East Granby | Site | 2002 |
| Clark, Avery, House | Southington | Building | 1989 |
| Clay Hill Historic District | Hartford | District | 1983 |
| Clay Hill Historic District (Boundary Increase) | Hartford | District | 1984 |
| Collins and Townley Streets District | Hartford | District | 1979 |
| Collinsville Historic District | Collinsville | District | 1976 |
| Colt Industrial District NHL | Hartford | District | 1976 |
| Colt Industrial District (Boundary Increase) | Hartford | District | 2003 |
| Colt, James B., House | Hartford | Building | 1975 |
| Colton, Benjamin, House | West Hartford | Building | 1986 |
| Commercial Trust Company Building | New Britain | Building | 2009 |
| Commercial Trust Company Building | New Britain | Building | 2009 |
| Congregational Church of Plainville | Plainville | Building | 2012 |
| Congress Street | Hartford | District | 1975 |
| Congress Street Historic District (Boundary Increase) | Hartford | Building | 1992 |
| Connecticut General Life Insurance Company Headquarters | Bloomfield | Building | 2010 |
| Connecticut State Capitol NHL | Hartford | Building | 1970 |
| Connecticut State Library and Supreme Court Building | Hartford | Building | 1981 |
| Connecticut Statehouse NHL | Hartford | Building | 1966 |
| Copper Ledges and Chimney Crest | Bristol | District | 1992 |
| Cossitt, Frederick H., Library | Granby | Building | 1988 |
| Coult, Abraham, House | Glastonbury | Building | 2000 |
| Cowles, Capt. Josiah, House | Southington | Building | 1989 |
| Cowles, Gen. George, House | Farmington | Building | 1982 |
| Curtisville Historic District | Glastonbury | District | 1992 |
| Darling, Robert and Julia, House | Simsbury | Building | 1991 |
| Day House | Hartford | Building | 1971 |
| Day, Calvin, House | Hartford | Building | 1978 |
| Day-Taylor House | Hartford | Building | 1975 |
| Deane, Silas, House NHL | Wethersfield | Building | 1970 |
| Department Store Historic District | Hartford | District | 1995 |
| Dillon Building | Hartford | Building | 1982 |
| Downtown Main Street Historic District | East Hartford | District | 1996 |
| Downtown New Britain | New Britain | District | 2016 |
| Downtown North Historic District | Hartford | District | 2004 |
| Drake Hill Road Bridge | Simsbury | Structure | 1984 |
| East Granby Historic District | East Granby | District | 1988 |
| East Weatogue Historic District | Simsbury | District | 1990 |
| East Windsor Academy | East Windsor | Building | 1998 |
| East Windsor Hill Historic District | South Windsor | District | 1986 |
| Elizabeth Park | West Hartford | Site | 1983 |
| Ellsworth, Horace H., House | Windsor | Building | 1988 |
| Ellsworth, Oliver, Homestead NHL | Windsor | Building | 1970 |
| Elm Street Historic District | Hartford | District | 1984 |
| Elm Street Historic District | Rocky Hill | District | 1998 |
| Elmore Houses | South Windsor | Building | 1985 |
| Endee Manor Historic District | Bristol | District | 1996 |
| Enfield Canal | Windsor Locks | Structure | 1976 |
| Enfield Carnegie Library | Enfield | Building | 2025 |
| Enfield Historic District | Enfield | District | 1979 |
| Enfield Shakers Historic District | Enfield | District | 1979 |
| Enfield Town Meetinghouse | Enfield | Building | 1974 |
| Engine Company 1 Fire Station | Hartford | Building | 1989 |
| Engine Company 15 Fire Station | Hartford | Building | 1989 |
| Engine Company 16 Fire Station | Hartford | Building | 1989 |
| Engine Company 2 Fire Station | Hartford | Building | 1989 |
| Engine Company 6 Fire Station | Hartford | Building | 1989 |
| Engine Company 9 Fire Station | Hartford | Building | 1989 |
| Eno Memorial Hall | Simsbury | Building | 1993 |
| Eno, Amos, House | Simsbury | Building | 1975 |
| Erwin Home for Worthy and Indigent Women | New Britain | Building | 2002 |
| Evans, Ebenezer, House | Southington | Building | 1989 |
| Fairfield Avenue Historic District | Hartford | District | 2011 |
| Farmington Canal-New Haven and Northampton Canal | Suffield | District | 1985 |
| Farmington Historic District | Farmington | District | 1972 |
| Farmington River Railroad Bridge | Windsor | Structure | 1972 |
| Farnsworth, Samuel, House | West Hartford | Building | 1986 |
| Federal Hill Historic District | Bristol | District | 1986 |
| Filley, Capt. Oliver, House | Bloomfield | Building | 2007 |
| First Church Parsonage | Windsor | Building | 1988 |
| First Church of Christ NHL | Farmington | Building | 1975 |
| First Church of Christ and the Ancient Burying Ground | Hartford | Building | 1972 |
| First Congregational Church of East Hartford and Parsonage | East Hartford | Building | 1982 |
| First Lutheran Church of the Reformation | New Britain | Building | 2010 |
| First National Bank Building | Hartford | Building | 1984 |
| Fitch, John, School | Windsor | Building | 1986 |
| Footguard Hall | Hartford | Building | 1984 |
| Forestville Passenger Station | Bristol | Building | 1978 |
| Former Fire Station | Windsor | Building | 1988 |
| Fourth Congregational Church | Hartford | Building | 1982 |
| Frog Hollow | Hartford | District | 1979 |
| Frog Hollow Historic District (Boundary Increase) | Hartford | District | 1984 |
| Frost, Levi B., House | Southington | Building | 1987 |
| Fuller Brush Company Factory Complex | Hartford | District | 2025 |
| Fuller, John, House | Suffield | Building | 1982 |
| Garvan-Carroll Historic District | East Hartford | District | 1991 |
| Gillett, Asa, House | West Hartford | Building | 1986 |
| Gillette, Francis, House | Bloomfield | Building | 1982 |
| Gilman-Hayden House | East Hartford | Building | 1984 |
| Glastonbury Historic District | Glastonbury | District | 1984 |
| Glastonbury-Rock Hill Ferry Historic District | Glastonbury | District | 2005 |
| Goodman, Timothy, House | West Hartford | Building | 1986 |
| Goodwin Block | Hartford | District | 1976 |
| Gothic Cottage | Suffield | Building | 1982 |
| Grace Church Rectory | Windsor | Building | 1988 |
| Granby Center Historic District | Granby | District | 1985 |
| Grandview Terrace Boulevard | Hartford | District | 2002 |
| Grannis, Stephen, House | Southington | Building | 1989 |
| Grant, Ebenezer, House | East Windsor Hill | Building | 1977 |
| Gridley-Parsons-Staples Homestead | Farmington | Building | 1981 |
| Hale, Dr. Elizur, House | Glastonbury | Building | 1989 |
| Hart's Corner Historic District | Burlington | District | 1987 |
| Hart, Timothy, House | Southington | Building | 1989 |
| Hartford & New Haven Railroad Depot | Windsor | Building | 1988 |
| Hartford & New Haven Railroad-Freight Depot | Windsor | Building | 1988 |
| Hartford Club | Hartford | Building | 1984 |
| Hartford Electric Light Company Maple Avenue Sub-Station | Hartford | Building | 2000 |
| Hartford Golf Club Historic District | West Hartford | District | 1986 |
| Hartford National Bank and Trust | Hartford | Building | 2016 |
| Hartford Seminary Foundation | Hartford | Building | 1982 |
| Hartford Special Machinery Company Complex | Hartford | District | 2022 |
| Hartford Union Station | Hartford | Building | 1975 |
| Harvey, William H., House | Windsor | Building | 1988 |
| Hastings Hill Historic District | Suffield | District | 1979 |
| Hathaways Store | Windsor | Building | 1988 |
| Hatheway House | Suffield | Building | 1975 |
| Hayden, Capt. Nathaniel, House | Windsor | Building | 1988 |
| Hayes, Samuel II, House | Granby | Building | 1992 |
| Hazardville Historic District | Hazardville and vicinity | District | 1980 |
| Heublein Tower | Simsbury | Building | 1983 |
| High Street Historic District | Hartford | District | 1998 |
| Hill-Stead NHL | Farmington | Building | 1991 |
| Hilltop Farm | Suffield | District | 2005 |
| Hitchcock-Schwarzmann Mill | Burlington | Building | 1977 |
| Holcomb, Judah, House | Granby | Building | 1988 |
| Holcomb, Nathaniel, III, House | Granby | Building | 1982 |
| Hollister, John, House | Glastonbury | Building | 1972 |
| Holmes, Francis H., House | New Britain | Building | 1984 |
| Hooker, Henry, House | Kensington | Building | 1978 |
| Hooker, John and Isabella, House | Hartford | Building | 1979 |
| Hooker, Sarah Whitman, House | West Hartford | Building | 1979 |
| Hosmer, Daniel, House | West Hartford | Building | 1986 |
| Hotel America | Hartford | Building | 2012 |
| House at 1010 Shuttle Meadow Road | Southington | Building | 1989 |
| House at 111 Maple Avenue | Windsor | Building | 1988 |
| House at 130 Hayden Station Road | Windsor | Building | 1988 |
| House at 140 and 144 Retreat Avenue | Hartford | Building | 1982 |
| House at 36 Forest Street | Hartford | Building | 1983 |
| House at 44 Court Street | Windsor | Building | 1988 |
| House at 590 West Street | Southington | Building | 1989 |
| House at 736 Palisado Avenue | Windsor | Building | 1988 |
| House at 847 Main Street, North | West Hartford | Building | 1986 |
| Hubbard Park | Meriden | Site | 1997 |
| Humphrey, John, House | Simsbury | Building | 1990 |
| Hurwood Company | Southington | Building | 1988 |
| Hyde-St. John House | Hartford | Building | 1977 |
| Imlay and Laurel Streets District | Hartford | District | 1979 |
| Isham-Terry House | Hartford | Building | 1982 |
| James Pratt Funeral Service | Hartford | Building | 1979 |
| Jefferson-Seymour District | Hartford | District | 1979 |
| Jerome, William I, House | Bristol | Building | 1987 |
| Johnson, Wilfred X., House | Hartford | Building | 1994 |
| Judd and Root Building | Hartford | Building | 1984 |
| Kellogg, Gen. Martin, House | Newington | Building | 1987 |
| Kelsey, Enoch, House | Newington | Building | 1982 |
| Kelsey, Ezekiel, House | Berlin | Building | 1977 |
| Keney Tower | Hartford | Building | 1978 |
| Kensington Grammar School-Jean E. Hooker High School | Berlin | Building | 2012 |
| Kensington Soldier's Monument | Berlin | Object | 2013 |
| Kimberly Mansion NHL | Glastonbury | Building | 1974 |
| King's Field House | Suffield | Building | 1982 |
| King, Alexander, House | Suffield | Building | 1976 |
| King, George, House | Sharon | Building | 2006 |
| Lake Compounce Carousel | Southington | Structure | 1978 |
| Landers, Frary and Clark Ellis Street Plant Historic District | New Britain | District | 2022 |
| Laurel and Marshall Streets District | Hartford | District | 1979 |
| Lewis Street Block | Hartford | District | 1976 |
| Lewis-Zukowski House | Suffield | Building | 1990 |
| Lighthouse Archeological Site (5-37) | Barkhamsted | Site | 1991 |
| Linke, William L., House | Hartford | Building | 1983 |
| Little Hollywood Historic District | Hartford | District | 1982 |
| Loomis, Capt. James, House | Windsor | Building | 1988 |
| Loomis, Col. James, House | Windsor | Building | 1988 |
| Loomis, George G., House | Windsor | Building | 1988 |
| Loomis, Gordon, House | Windsor | Building | 1988 |
| Loomis, Ira, Jr., House | Windsor | Building | 1988 |
| Lyman House | Hartford | Building | 1975 |
| Magill, Henry, House | Windsor | Building | 1988 |
| Main Street Historic District | Bristol | District | 1995 |
| Main Street Historic District | Manchester | District | 1996 |
| Main Street Historic District No. 2 | Hartford | District | 1984 |
| Manchester Historic District | Manchester | District | 2000 |
| Manchester Historic District (Boundary Increase) | Manchester | District | 2001 |
| Mansuy and Smith Automobile Showroom Building | Hartford | Building | 2016 |
| Marion Historic District | Southington | District | 1988 |
| Marlborough Congregational Church | Marlborough | Building | 1993 |
| Marlborough House | Bristol | Building | 1993 |
| Marlborough Tavern | Marlborough | Building | 1978 |
| Masonic Temple | New Britain | Building | 1995 |
| Massacoe Forest Pavilion | Simsbury | Building | 1986 |
| Mather Homestead | Hartford | Building | 1982 |
| Melrose | East Windsor | District | 2010 |
| Melrose Road Bridge | East Windsor | Structure | 1999 |
| Memorial Hall | Windsor Locks | Building | 1987 |
| Meriden Avenue-Oakland Road Historic District | Southington | District | 1988 |
| Metropolitan African Methodist Episcopal Zion Church | Hartford | Building | 1994 |
| Mills, Elijah, House | Windsor | Building | 1985 |
| Mills, Oliver W., House | Windsor | Building | 1982 |
| Mills, Timothy Dwight, House | Windsor | Building | 1988 |
| Montgomery, J.R., Company Industrial Complex | Windsor Locks | District | 2017 |
| Moore, Deacon John, House | Windsor | Building | 1977 |
| Moore, Edward and Ann, House | Windsor | Building | 1988 |
| Moore, Roswell, II, House | Southington | Building | 2005 |
| Morley, Edward W., House NHL | West Hartford | Building | 1975 |
| Mount St. Joseph Academy | West Hartford | Building | 1983 |
| Municipal Building | Hartford | Building | 1981 |
| Murphy, Patrick, House | Windsor | Building | 1988 |
| Myers and Gross Building | Hartford | Building | 1983 |
| Naubuc Avenue-Broad Street Historic District | East Hartford | District | 1998 |
| Neiditz Building | Hartford | Building | 2020 |
| New Britain Opera House | New Britain | Building | 1977 |
| New Britain Public High School Campus | New Britain | Building | 2015 |
| New Haven District Campground | Plainville | District | 1980 |
| Newington Junction North Historic District | Newington | District | 1987 |
| Newington Junction Railroad Depot | Newington | Building | 1986 |
| Newington Junction South Historic District | Newington | District | 1987 |
| Newington Junction West Historic District | Newington | Building | 1987 |
| Newington VA Hospital Historic District | Newington | District | 2022 |
| Nook Farm and Woodland Street District | Hartford | District | 1979 |
| North-West School | Hartford | Building | 2010 |
| Northam Memorial Chapel and Gallup Memorial Gateway | Hartford | Building | 1982 |
| Norton, Charles H., House NHL | Plainville | Building | 1976 |
| O'Connell, Clara T., School | Bristol | Building | 2017 |
| Old Farm Schoolhouse | Bloomfield | Building | 1972 |
| Old Newgate Prison NHL | East Granby | Site | 1970 |
| Old North Cemetery | Hartford | Site | 1998 |
| Old Wethersfield Historic District | Wethersfield | District | 1970 |
| Oxford-Whitney Streets Historic District | Hartford | District | 2010 |
| Palisado Avenue Historic District | Windsor | District | 1987 |
| Parkside Historic District | Hartford | District | 1984 |
| Parkville Historic District | Hartford | District | 2015 |
| Payne, Daniel, House | Windsor | Building | 1988 |
| Peck, Stow & Wilcox Factory | Southington | Building | 1988 |
| Pequabuck Bridge | Farmington | Structure | 1984 |
| Perkins-Clark House | Hartford | Building | 1978 |
| Phelps, Capt. Elisha, House | Simsbury | Building | 1972 |
| Phelps, Eli, House | Windsor | Building | 1988 |
| Phelps, Ezekiel, House | East Granby | Building | 1982 |
| Phoenix Life Insurance Company Building | Hartford | Building | 2005 |
| Pine Grove Historic District | Avon | District | 1980 |
| Pinney, David, House and Barn | Windsor Locks | Building | 1977 |
| Pinney, David, House and Barn (Boundary Increase) | Windsor Locks | Building | 1994 |
| Pitkin Glassworks Ruin | Manchester | Site | 1979 |
| Plantsville Historic District | Southington | District | 1988 |
| Polish National Home | Hartford | Building | 1983 |
| Pomeroy, Arthur G., House | Hartford | Building | 1982 |
| Porter, Dr. J., House | Southington | Building | 1989 |
| Pratt Street Historic District | Hartford | District | 1983 |
| Prospect Avenue Historic District | Hartford | District | 1985 |
| Pultz & Walkley Company | Southington | Building | 1988 |
| Revolutionary War Campsite | West Hartford | Site | 1986 |
| Robbins, John, House | Rocky Hill | Building | 1988 |
| Robbins, Unni II, House | Newington | Building | 2005 |
| Rockwell Park | Bristol | District | 1987 |
| Rocky Hill Center Historic District | Rocky Hill | District | 2007 |
| Rocky Hill Congregational Church | Rocky Hill | Building | 1982 |
| Root, Jonathan, House | Southington | Building | 1989 |
| Rowe and Weed Houses | Granby | Building | 1978 |
| Royal Typewriter Company Building | Hartford | Building | 1989 |
| Saint Anthony Hall | Hartford | Building | 1985 |
| Second Church of Christ | Hartford | Building | 1978 |
| Seymour, Elisha, Jr., House | West Hartford | Building | 1986 |
| Shade Swamp Shelter | Farmington | Building | 1986 |
| Shelton, William, House | Windsor | Building | 1988 |
| Sigourney Square District | Hartford | District | 1979 |
| Sigourney Square Historic District (Boundary Increase II) | Hartford | Building | 2011 |
| Sigourney Square Historic District (Boundary Increase) | Hartford | District | 1983 |
| Simeon North Factory Site | Berlin | Site | 1990 |
| Simpson, Dr. Frank T., House | Hartford | Building | 1993 |
| Simsbury Bank and Trust Company Building | Simsbury | Building | 1986 |
| Simsbury Center Historic District | Simsbury | District | 1996 |
| Simsbury Railroad Depot | Simsbury | Building | 1976 |
| Simsbury Townhouse | Simsbury | Building | 1993 |
| Sisson-South Whitney Historic District | Hartford | District | 2013 |
| Skelton, Dr. Henry, House | Southington | Building | 1989 |
| Sloper-Wesoly House | New Britian | Building | 1999 |
| Smith, H. D., Company Building | Plantsville | Building | 1977 |
| South Congregational Church | New Britain | Building | 1990 |
| South End Historic District | Bristol | District | 2001 |
| South Glastonbury Historic District | Glastonbury | District | 1984 |
| South Glastonbury Historic District Boundary Increase | Glastonbury | District | 2009 |
| South Green Historic District | Hartford | District | 1977 |
| Southern New England Telephone Company Building | Hartford | Building | 2004 |
| Southington Center Historic District | Southington | District | 1989 |
| Southington Public Library | Southington | Building | 1989 |
| Southwest District School | Bloomfield | Building | 1992 |
| Spanish House, The | West Hartford | Building | 1979 |
| Spencer House | Hartford | Building | 1983 |
| Spring Grove Cemetery | Hartford | District | 2010 |
| St. John's Episcopal Church | Warehouse Point | Building | 1982 |
| St. John's Episcopal Church | East Hartford | Building | 1983 |
| St. Mary's Parochial School | New Britain | Building | 1991 |
| St. Paul's Methodist Episcopal Church | Hartford | Building | 1984 |
| Stackpole, Moore, and Tryon Building | Hartford | Building | 1978 |
| Stafford Hollow Historic District | Stafford | District | 1987 |
| Stanley-Whitman House NHL | Farmington | Building | 1966 |
| Stanley-Woodruff-Allen House | West Hartford | Building | 1986 |
| State Arsenal and Armory | Hartford | Building | 1996 |
| Steele, Allyn, House | West Hartford | Building | 1986 |
| Stone Bridge | Hartford | Structure | 1985 |
| Stony Hill School | Windsor | Building | 1988 |
| Stowe, Harriet Beecher, House NHL | Hartford | Building | 1970 |
| Sts. Cyril and Methodius Church | Hartford | Building | 1983 |
| Suffield Historic District | Suffield | District | 1979 |
| Sweetland, Sophia, House | Windsor | Building | 1988 |
| Swift, M. and Sons Company | Hartford | Building | 2013 |
| Tariffville Historic District | Simsbury | District | 1993 |
| Temple Beth Israel | Hartford | Building | 1978 |
| Temple Beth Israel | West Hartford | Building | 1995 |
| Tephereth Israel Synagogue | New Britain | Building | 1995 |
| Terry's Plain Historic District | Simsbury | District | 1993 |
| Terry-Hayden House | Bristol | Building | 1982 |
| Thompson, William H., Farmstead | East Windsor | Building | 2003 |
| Town Bridge | Canton | Structure | 1999 |
| Treadway, Townsend G., House | Bristol | Building | 1991 |
| Treadwell House | Burlington | Building | 1982 |
| Trinity College Long Walk Historic District | Hartford | District | 2024 |
| Trinity Methodist Episcopal Church | New Britain | Building | 2007 |
| Tunxis Forest Headquarters House | Hartland | Building | 1986 |
| Tunxis Forest Ski Cabin | Hartland | Building | 1986 |
| Twain, Mark, House NHL | Hartford | Building | 1966 |
| U. S. Post Office and Federal Building | Hartford | Building | 1981 |
| US Post Office-Manchester Main | Manchester | Building | 1986 |
| Underwood Computing Machine Company Factory | Hartford | Building | 2010 |
| Union Baptist Church | Hartford | Building | 1979 |
| Union Village Historic District | Manchester | District | 2002 |
| Upper Albany Historic District | Hartford | District | 1986 |
| Viets' Tavern | East Granby | Building | 1972 |
| Vine Street Apartment Buildings | Hartford | District | 2012 |
| Wadsworth Atheneum | Hartford | Building | 1970 |
| Walnut Hill District | New Britain | District | 1975 |
| Walnut Hill Park | New Britain | Site | 1982 |
| Washington School | New Britain | Building | 1984 |
| Washington Street School | Hartford | Building | 1982 |
| Watkinson Juvenile Asylum and Farm School | Hartford | District | 1995 |
| Webb, Joseph, House NHL | Wethersfield | Building | 1966 |
| Webster Memorial Building | Hartford | Building | 1982 |
| Webster, Horace, Farmhouse | Southington | Building | 1977 |
| Webster, Noah, Birthplace NHL | West Hartford | Building | 1966 |
| Webster, Noah, Memorial Library | West Hartford | Building | 1981 |
| Welles, Gideon, House | Glastonbury | Building | 1970 |
| Welles-Shipman-Ward House | South Glastonbury | Building | 1977 |
| Wells, John, Jr., House | West Hartford | Building | 1986 |
| West Boulevard Historic District | Hartford | District | 2007 |
| West End Historic District | New Britain | District | 1998 |
| West End Library | Farmington | Building | 2000 |
| West End North Historic District | Hartford | District | 1985 |
| West End South Historic District | Hartford and West Hartford | District | 1985 |
| West Granby Historic District | Granby | District | 1992 |
| West Hill Historic District | West Hartford | District | 1996 |
| West Street School | Southington | Building | 1988 |
| Wethersfield Avenue Car Barn | Hartford | Building | 1983 |
| Whitfield Cowles House | East Granby | Building | 2014 |
| Whiting Homestead | West Hartford | Building | 1987 |
| Whitman House | West Hartford | Building | 1986 |
| Wiard, John, House | Burlington | Building | 1982 |
| Widows' Home | Hartford | Building | 1983 |
| Wightman, Rev. John, House | Southington | Building | 1989 |
| Wightman, Valentine, House | Southington | Building | 1989 |
| Willard Homestead | Newington | Building | 1986 |
| Williams, Austin F., Carriagehouse and House NHL | Farmington | Building | 1998 |
| Williams, J. B., Co. Historic District | Glastonbury | District | 1983 |
| Windsor Avenue Congregational Church | Hartford | Building | 1993 |
| Windsor Farms Historic District | South Windsor | District | 1986 |
| Windsor Locks Passenger Station | Windsor Locks | Building | 1975 |
| Woodbridge Farmstead | Manchester | Building | 1999 |
| Woodruff House | Southington | Building | 1989 |
| Woodruff, Capt. Samuel, House | Southington | Building | 1989 |
| Woodruff, Ezekiel, House | Southington | Building | 1989 |
| Woodruff, Jotham, House | Southington | Building | 1989 |
| Woodruff, Urbana, House | Southington | Building | 1989 |
| Worthington Ridge Historic District | Berlin | District | 1989 |