| John McMahon | |
| Fullname: | John Sydney McMahon |
| Birth Date: | 4 October 1900 |
| Birth Place: | South Yarra, Victoria |
| Death Place: | Rutherglen, Victoria |
| Originalteam: | South Yarra |
| Height: | 165cm |
| Weight: | 56 kg |
| Statsend: | 1919 |
| Years1: | 1919 |
| Games Goals1: | 3 (0) |
John Sydney McMahon was an Australian rules footballer who played with Melbourne in the Victorian Football League (VFL).[1]