The Illinois Republican Party is the affiliate of the Republican Party in Illinois. As of 2005, it has been headed by Andrew McKenna, State Chairman. The party is one of only three legally established, statewide political parties in Illinois, the others being the Democratic and Green parties.
| Chairman | Term |
|---|---|
| Rebecca Paul | co-chairman ~1985 with Adams |
| Victor L. Smith | 1960–1973 |
| Donald "Doc" Adams | 1973–1988 |
| Al Jourdan | 1988–1993 |
| Harold Byron Smith | 1993–1999 |
| Rich Williamson | 1999–2002 |
| Lee A. Daniels | 2001–2002 |
| Dallas Ingemunson | 2002 (interim) |
| Gary MacDougal | 2002–2002 |
| Judy Baar Topinka | 2002–2005 |
| Andrew McKenna | 2005–Present |