Reid's best-known film role was as Ernie Malone, private detective hired to spy on Marilyn Monroe's character, only to become Jane Russell's love interest, in the 20th Century Fox classic Gentlemen Prefer Blondes (1953).
Reid played Professor Shelby Ashton in two Walt Disney movies starring Fred MacMurray: The Absent-Minded Professor in 1961, and sequel Son of Flubber in 1963.