Mars Callahan
- Luogo di nascita:
- Studio City, California, U.S.:
 | Dog Patrol (2025) Agent Matters |
 | Poolhall Junkies (2002) Johnny |
 | That Thing You Do! (1996) Ernie the Disc Master Engineer |
 | Clifford (1994) Brian |
 | Kalifornia (1993) Walter Livesy |
 | Highway to Hell (1991) State Policeman |
 | The Children of Times Square (1986) Brian (as Gregory 'Mars' Martin) |