| Birth Date: | 28 October 1945 |
| Birth Place: | Baltimore, Maryland, U.S. |
| Death Place: | Ottawa, Ontario, Canada |
| Import: | yes |
| Position1: | Linebacker |
| Height Ft: | 6 |
| Height In: | 0 |
| Weight Lb: | 235 |
| Highschool: | Patterson (Baltimore, Maryland) |
| College: | Oklahoma |
| Playing Years1: | 1968–1969 |
| Playing Team1: | Pottstown Firebirds |
| Playing Years2: | – |
| Playing Team2: | Montreal Alouettes |
| Playing Years3: | – |
| Playing Team3: | Hamilton Tiger-Cats |
| Playing Years4: | – |
| Playing Team4: | Ottawa Rough Riders |
| Cflallstar: | , |
| Cfleastallstar: | ,, |
| Awards: | 1971 CFL's Most Outstanding Lineman runner up |
Mark Kosmos (October 28, 1945 – November 11, 2020) was an American football player in the ACFL, for the Pottstown Firebirds in 1968 and 1969 and in the CFL for eight years. He played linebacker for the Montreal Alouettes, Hamilton Tiger-Cats and Ottawa Rough Riders from 1970 to 1977. Kosmo played college football at the University of Oklahoma.
Kosmos died in Ottawa in November 2020.[1] He was afflicted with dementia symptoms and contracted COVID-19 in the time leading up to his death, amid the COVID-19 pandemic in Ottawa.[2] [3]