Down in San Diego is a 1941 American adventure film directed by Robert B. Sinclair and written by Franz Schulz and Harry Clork.

The black-and-white movie was filmed in San Diego and stars Bonita Granville, Ray McDonald, Dan Dailey, Leo Gorcey, Henry O'Neill and Stanley Clements.

Hank Parker is turned down by the U.S. Marine Corps for being too young, but his girlfriend Betty's older brother Al Haines is not.

Al, however, is blackmailed by former criminal associates, framed for the murder of a man named Matt Herman if he refuses to spy for the crooks, who will sell the information to American enemies for a profit.

Al discloses to superior officer Col. Halliday that the criminals want him to steal a Navy boat on the Germans' behalf.