| Elgin Academy | 350 Park Street | October 8, 1976 |
| Gifford-Davidson House | 363-365 Prairie Street | May 31, 1980 |
| First Universalist Church | 55 Villa, 263 DuPage | November 7, 1980 |
| Ora Pelton House | 214 South State Street | August 12, 1982 |
| Elgin Historic District | Bounded by Villa, Center Park, North Liberty, and South Channing Streets | May 9, 1983 |
| Fire Barn No. 5 | 533 St. Charles Road | August 5,1991 |
| Elgin National Watch Company Observatory | 312 Watch Street | August 16, 1994 |
| Memorial Washington Reformed Presbyterian Church | West Highland Avenue | November 19, 1980 |
| Spring-Douglas Historic District | Bounded by Douglas Avenue, Spring Street River, Bluff Road, and Kimball Avenue | April 28, 2000 |
| Elgin Tower Building | 100 E. Chicago Street | May 22, 2002 |
| Wing Park Golf Course | 1000 Wing Street | February 2008 |
| Downtown Elgin Commercial District | Bounded by Center Street, Prairie Street, Kimball Ave and the Fox River | December 2014 |