Stranger on the Third Floor (1940) is a film noir thriller, featuring Peter Lorre, co-written by Nathaniel West, and released by RKO Radio Pictures. The picture was directed by Boris Ingster.

It is often referred to as the first "true" film noir of the classic period (1940-1959). It has many of the hallmarks of noir: an urban setting, heavy shadows, diagonal lines, low camera angles shooting up multi-storey staircases, and an innocent protagonist falsely accused of a crime and desperate to clear himself.

Rising reporter Michael Ward is a key witness in the murder trial of young Joe Briggs, who is convicted on circumstantial evidence while swearing innocence. Mike's girl Jane believes in Joe and blames Mike, who (in a remarkable sequence) dreams he is himself convicted of murdering his nosy neighbor. Will his dream come true before Jane can find the real murderer? Written by Rod Crawford

A newspaper reporter gives truthful but circumstantial evidence at the murder trial of pathetic loser Briggs. Briggs is convicted despite crying his innocence and the reporter begins to feel guilty for the key role he played in the trial. Haunted by memories of the poor man's pleas, he begins to wonder... Written by Ken Yousten