| István Ács | |
| Order: | Chairman of the Council of Debrecen |
| Term Start: | 11 October 1966 |
| Term End: | 31 December 1989 |
| Predecessor: | Gábor Szilágyi |
| Successor: | József Hevessy as Mayor of Debrecen |
| Birth Date: | 18 September 1928 |
| Birth Place: | Nádudvar, Hungary |
| Death Place: | Debrecen, Hungary |
| Profession: | jurist, politician |
Dr. István Ács (September 18, 1928 – July 22, 2018) was a Hungarian jurist and politician, who served as the last Chairman of the Council of Debrecen between October 11, 1966 and December 31, 1989.