The Silent Partner is a 1978 Canadian thriller film directed by Daryl Duke and starring Elliott Gould, Christopher Plummer, and Susannah York. The screenplay by Curtis Hanson is based on the novel Think of a Number (Tænk på et tal) by Danish writer Anders Bodelsen.

The film is about Miles Cullen (Gould), a Toronto bank teller, who discovers a discarded holdup note revealing an imminent robbery. Suspecting the mall Santa, Harry Reikle (Plummer), Miles secretly hides $48,300 from his transactions in a lunchbox, giving Reikle only a small amount during the robbery. Realizing he's been shorted, Reikle stalks and threatens Miles.

The Silent Partner, based on Anders Bodelson's 1969 suspense novel, was adapted into a screenplay by Curtis Hanson, who initially hoped to direct but was not selected. The lead role went to Elliott Gould, who praised the script as one of the best he'd read. Directed by Daryl Duke, the film marked Carolco Pictures' first production and benefited from Canada's Capital Cost Allowance incentive, promoting domestic filmmaking. Post-production saw Hanson return to handle pick-up shots and editing after producers added a beheading scene, a decision opposed by Duke who left the project.

Reviews of The Silent Partner praise its intelligent, suspenseful storytelling, engaging characters, and skilled direction. Critics highlight its Hitchcockian tension, clever plotting, and the seamless blend of intrigue and violence. The cast, including Susannah York, Christopher Plummer, and Elliott Gould, is commended for their performances. While some noted flaws, most of it was outweighed by the film's gripping and entertaining execution, making it a critical success. It also won three Canadian Film Awards including Best Feature Film and Best Direction.