| Year: | 2021 |
| Team: | LIU Sharks |
| Sport: | football |
| Conference: | Northeast Conference |
| Short Conf: | NEC |
| Record: | 2–8 |
| Conf Record: | 2–5 |
| Head Coach: | Jonathan Gill |
| Hc Year: | interim |
| Off Coach: | Jim Cordle |
| Oc Year: | 2nd |
| Def Coach: | Rich Reichert |
| Dc Year: | 2nd |
| Stadium: | Bethpage Federal Credit Union Stadium |
The 2021 LIU Sharks football team represented both the LIU Post and LIU Brooklyn campuses of Long Island University as a member of the Northeast Conference (NEC) in the 2021 NCAA Division I FCS football season. The Sharks, led by interim head coach Jonathan Gill, played their home games at Bethpage Federal Credit Union Stadium.
See also: 2021 FIU Panthers football team.