Gene Hackman
John Cazale
Allen Garfield
Frederic Forrest
Cindy Williams
Michael Higgins
Elizabeth MacRae
Teri Garr
Harrison Ford
Mark Wheeler
Gene Hackman as Harry Caul
John Cazale as Stan
Allen Garfield as William P. 'Bernie' Moran
Frederic Forrest as Mark
Cindy Williams as Ann
Michael Higgins as Paul
Elizabeth MacRae as Meredith
Teri Garr as Amy Fredericks
Harrison Ford as Martin Stett
Mark Wheeler as Receptionist
Robert Shields as The Mime
Phoebe Alexander as Lurleen
Ramon Bieri as Man at party (uncredited)
Gian-Carlo Coppola as Boy in Church (uncredited)
Robert Duvall as The Director (uncredited)