| Nikola Aćin | |
| Strokes: | Freestyle, backstroke |
| Club: | PK Proleter Zrenjanin |
| Collegeteam: | Purdue Boilermakers, Michigan Wolverines |
| Birth Date: | 19 December 1999 |
| Birth Place: | Zrenjanin, FR Yugoslavia |
Nikola Aćin (born 19 December 1999) is a Serbian swimmer. He competed in the men's 4 × 100 metre freestyle relay event at the 2020 Summer Olympics together with Andrej Barna, Uroš Nikolić and Velimir Stjepanović.[1] They finished 10th with time 3:13.71, setting the new Serbian national record.[2]