Zero Effect is a 1998 mystery film written and directed by Jake Kasdan (son of writer/director Lawrence Kasdan). It stars Bill Pullman as "the world's most private detective" Daryl Zero and Ben Stiller as his assistant Steve Arlo. It was clearly inspired by Rex Stout's series of Nero Wolfe mystery stories, which were similarly about a housebound detective (Nero = Zero) and his faithful legman (Archie = Arlo). The plot of the film is loosely based on the Arthur Conan Doyle short story A Scandal in Bohemia.

The film was shot in Portland, Oregon. It was scored by The Greyboy Allstars. It was screened in the Un Certain Regard section at the 1998 Cannes Film Festival.