| Sergio Marchi | |
| Birth Date: | 22 May 1920 |
| Birth Place: | Pisa, Kingdom of Italy |
| Death Place: | Pisa, Italy |
| Position: | Defender |
| Years1: | 1936–1938 |
| Years2: | 1938–1943 |
| Years3: | 1943–1944 |
| Years4: | 1944–1945 |
| Years5: | 1945–1948 |
| Years6: | 1948–1950 |
| Clubs3: | Pisa |
| Clubs6: | Cagliari |
| Caps1: | 42 |
| Goals1: | 2 |
| Caps2: | 132 |
| Goals2: | 0 |
| Caps4: | 17 |
| Goals4: | 0 |
| Caps5: | 88 |
| Goals5: | 0 |
| Caps6: | 32 |
| Goals6: | 0 |
| Nationalyears1: | 1939 |
| Nationalteam1: | Italy |
| Nationalcaps1: | 1 |
| Nationalgoals1: | 0 |
Sergio Marchi (pronounced as /it/; born 22 May 1920 – 16 December 1979) was an Italian professional footballer who played as a defender.