Thomas Donnelly may refer to:
- Thomas Donnelly (Saskatchewan politician) (Thomas F. Donnelly, 1874–1948), Canadian member of Parliament
- Thomas Donnelly (sergeant-at-arms) (1764–1835), New York legislative officer
- Thomas Donnelly (Alberta politician) (1933–1997), Alberta MLA
- Thomas Dean Donnelly, American screenwriter
- Thomas F. Donnelly (New York City) (1863–1924), New York politician and judge
- Tom Donnelly (Thomas Mathew Donnelly, born 1981), New Zealand rugby union player
- Tommy Donnelly (footballer), Irish association football player
- Tom Donnelly (footballer) (born 1947), Scottish footballer
- Tom Donnelly (runner), winner of the 1968 distance medley relay at the NCAA Division I Indoor Track and Field Championships