Aún no disponemos de datos de John Mahon en la Base
Filmografía parcial 
| --<>-- | ||
| All -- Movies -- TVmovie-Video -- TV Episodes | ||
| - |  ARMAGEDDON (1998) ... Karl | |
| - | X-FILES 6/121 DREAMLAND (1998) ... Gen. Wegman | |
| - | X-FILES 6/122 DREAMLAND II (1998) ... Gen. Wegman | |
| - | L.A. CONFIDENTIAL (1997) ... Jefe de Policía | |
| - | NATURAL SELECTION (1994) ... Dickler | |
| - | PEOPLE UNDER THE STAIRS, THE (1991) ... Policía | |
| - | BAD INFLUENCE (1990) ... Dr. Fielding | |
| - | KNIGHT RIDER 4/77 KNIGHT RACER (1985) ... Girdler | |
| - | SOMEONE'S WATCHING ME! (1978) ... Frimsin | |
