Connecticut - Area of significance: Industry
| Aeolian Company Factory Complex |
| Allen's Cider Mill |
| American Mills Web Shop |
| American Thermos Bottle Company Laurel Hill Plant |
| American Thread Company |
| Ann Street Historic District |
| Armsmear |
| Armstrong, M. and Company Carriage Factory |
| Atwater Manufacturing Company |
| Ball and Roller Bearing Company |
| Baltic Historic District |
| Barber, Giles, House |
| Beckley Furnace |
| Belltown Historic District |
| Benedict House and Shop |
| Bigelow-Hartford Carpet Mills |
| Bigelow-Hartford Carpet Mills Historic District |
| Black Rock Historic District |
| Blakeslee Forging Company |
| Brayton Grist Mill |
| Broad Brook Company |
| Broad Street Green Historic District |
| Brooks, Hervey, Pottery Shop and Kiln Site |
| Butts Bridge |
| Cain, Hugh, Fulling Mill and Elias Glover Woolen Mill Archeological Site |
| Capewell Horse Nail Company |
| Cargill Falls Mill (Wilkinson Mill) |
| Carpenter, Joseph, Silversmith Shop |
| Case, Benomi, House |
| Case Brothers Historic District |
| Catlin, J. Howard, House |
| Central Village Historic District |
| Chapin, Philip, House |
| Chapman, Taylor, House |
| Cheney Brothers Historic District |
| Church of the Good Shepherd and Parish House |
| Clark Brothers Factory No. 1 |
| Clark Brothers Factory No. 2 |
| Coffing, John C., House |
| Collinsville Historic District |
| Colt Industrial District |
| Commonwealth Works Site |
| Cos Cob Power Station |
| Cove Island Houses |
| Coventry Glass Factory Historic District |
| Curtisville Historic District |
| Daniel's Village Archeological Site |
| D & H Scovil Industrial Historic District |
| Doane's Sawmill/Deep River Manufacturing Company |
| Downtown Seymour Historic District |
| Dwight Street Historic District |
| East Bridgeport Historic District |
| East Haddam Historic District |
| Edward Bloom Silk Company Factory |
| Eldredge Mills Archeological District |
| Elliottville Lower Mill |
| Ellsworth, Horace H., House |
| EMMA C. BERRY (Fishing Sloop) |
| Enfield Canal |
| Filley, Capt. Oliver, House |
| First Church Parsonage |
| Florence Mill |
| Forbes, Samuel, Homestead |
| Former Fire Station |
| Frog Hollow |
| Fuller Brush Company Factory Complex |
| Gallaher Estate |
| Georgetown Historic District |
| Gilbert Clock Factory |
| Gillette's Grist Mill |
| Glen Falls Bridge |
| Goshen Historic District |
| Grace Church Rectory |
| Greeneville Historic District |
| Groton Bank Historic District |
| Gurleyville Historic District |
| Hallville Mill Historic District |
| Halpine, J. S., Tobacco Warehouse |
| Hammanasset Paper Mill Site |
| Hartford & New Haven Railroad Depot |
| Hartford & New Haven Railroad-Freight Depot |
| Hartford Special Machinery Company Complex |
| Harvey, William H., House |
| Hathaways Store |
| Hattertown Historic District |
| Hayden, Capt. Nathaniel, House |
| Hayward House |
| Hazardville Historic District |
| Hemlock Glen Industrial Archeological District |
| Hempstead Historic District |
| Heublein Tower |
| Highland Historic District |
| High Street Historic District |
| Hitchcock-Schwarzmann Mill |
| Hollister, Homestead, The |
| Holmes, Francis H., House |
| Home Woolen Company |
| Hooker, Henry, House |
| Hotchkissville Historic District |
| House at 111 Maple Avenue |
Data from United States Park Service and Wikidata
