| Frank Cassidy | |
| Nationality: | American |
| Sport: | Boxing |
| Birth Date: | 7 December 1895 |
| Birth Place: | New York, New York, United States |
Frank Cassidy (November 7, 1895 - February 28, 1924) was an American boxer.[1] He competed in the men's lightweight event at the 1920 Summer Olympics.[2] At the 1920 Summer Olympics, he defeated Ko Janssens of the Netherlands in his first fight, before being eliminated by Gotfred Johansen of Denmark in the quarterfinals.[2]