The Undercover Man is a 1949 American crime film noir directed by Joseph H. Lewis and starring Glenn Ford, Nina Foch and James Whitmore.

The film was based on an article titled "He Trapped Capone," the first part of the autobiography Undercover Man by Federal Agent Frank J. Wilson, which was serialized in Collier's in 1947.

Al Capone was referred to only as the shadowy "Big Fellow" and photographed only from the rear and was a more diversified mobster rather than primarily a bootlegger (reflecting the change in US organized crime following Prohibition's repeal).

"[3] The staff at Variety magazine gave the film a positive review, writing: "Narrated in a straightforward, hardhitting documentary style, The Undercover Man is a good crime-busting saga.

And Lewis - one of the B movie greats - directs in admirably forthright, muscular fashion, making superb use of Burnett Guffey's gritty monochrome camerawork.