Laraine Day (October 13, 1920 – November 10, 2007) was an American actress and a former MGM contract star.

Born La Raine Johnson in Roosevelt, Utah, to an affluent Mormon family, she later moved to California where she began her acting career with the Long Beach Players. She was a 1938 graduate of Polytechnic High School in Long Beach, California.

In 1937, Day debuted onscreen in a bit part in Stella Dallas. Shortly afterwards, she won lead roles in several George O'Brien westerns at RKO, in which she was billed as "Laraine Hays" and then "Laraine Johnson".

In 1939 she signed with MGM, and became popular and well-known (billed as Laraine Day) as "Nurse Mary Lamont", the title character's fiancee in a string of seven "Dr. Kildare" movies beginning with Calling Dr. Kildare (1939), with Lew Ayres in the title role.

Her roles for other studios were often far more stimulating than those MGM gave her, including a prominent supporting part in the Irish melodrama My Son, My Son! (1940). She also starred in the Alfred Hitchcock thriller Foreign Correspondent (1940) with Joel McCrea, and the psychological mystery The Locket (1946) with Robert Mitchum, Brian Aherne, and Gene Raymond. In 1941 she was voted the number one "star of tomorrow" in Hollywood.