Mr. Moto's Gamble is a film in the Mr. Moto series released in 1938 that stars Peter Lorre. It was originally intended to be a Charlie Chan film called Charlie Chan at Ringside, but Warner Oland, who had played Chan in several previous films, left the set after a few days of filming, and died while on vacation in his native Sweden, several months after Mr. Moto's Gamble was completed and released. The script was rewritten as a Mr. Moto movie, featuring Keye Luke as Lee Chan (in his only appearance in the Mr. Moto series) as Mr. Moto's student in his criminology class at San Francisco University.

A tribute to Warner Oland appears in the next film in the Moto series, Mr. Moto's Last Warning (1939). During the movie's production in August 1938, the cast and crew learned of Warner Oland's passing in Sweden. On the marquee for the Sultana Theatre of Variety, the banner "Last Day" was placed over the title "Charlie Chan in Honolulu", the movie on the theater's bill.

Mr. Moto must discover who poisoned a fighter in the boxing ring. This movie began as "Charlie Chan at the Ringside," but Warner Oland abruptly quit during filming, so it was rewritten as a Mr. Moto film. Written by Ed Stephan

A boxer dies in the prizefight ring, and detective Mr. Moto is called in when it turns out to be murder. What Moto uncovers, with the help of Charlie Chan's son Lee, is a gangland gambling racket. Written by Jim Beaver