A time capsule of the L.A. comedy scene in the 1970s, "Diary of a Young Comic" casts Richard Lewis as a fictionalized version of himself - a young New York comic who comes out to Los Angeles to seek his fame and fortune.
| Actor | Role |
|---|---|
 Richard LewisBilly Goldstein / Gondola | Billy Goldstein / Gondola |
| DDom DeLuiseHimself | Himself |
 George JesselHimself | Himself |
 Bill MacyHerbert Gondolstein | Herbert Gondolstein |
 Stacy KeachMr. Porzinski | Mr. Porzinski |
 Michael LernerNorman Greenleaf - Billy's agent | Norman Greenleaf - Billy's agent |
 Linda KerridgeBilly's neighbor | Billy's neighbor |
 Gary Mule DeerHimself | Himself |
 Nina van PallandtHerself | Herself |
 Richard DimitriDr. Alexander Biff Mendez - Billy's therapist | Dr. Alexander Biff Mendez - Billy's therapist |
| GGypsy BootsHimself | Himself |
| MMarvin BravermanNot listed | Not listed |
 Bernie BrillsteinHimself | Himself |
| TTony DeLiaNot listed | Not listed |
 Murphy DunneNot listed | Not listed |
 Budd FriedmanHimself | Himself |
 Bryan GordonNot listed | Not listed |
 Bunny SummersBunny Gondolstein | Bunny Gondolstein |
 Tim ThomersonLucifer | Lucifer |