Arthur O'Connell (March 29, 1908 – May 18, 1981) was an American stage and film actor. He appeared in films (starting with a small role in Citizen Kane) from 1941 and took part in television programs (mostly as a guest star). Among his screen work were Picnic, Anatomy of a Murder, and the role of a watchmaker who hid Jews during World War II in the film The Hiding Place.

A vaudeville veteran, O'Connell, a native of New York City, made his professional stage debut in the mid-1930s, when he came into the orbit of Orson Welles's Mercury Theatre. Welles gave O'Connell a tiny role as a reporter in the closing scenes of Citizen Kane (1941), a film often called O'Connell's screen debut, although he had in fact already appeared in Freshman Year (1939) and had starred in two Leon Errol shorts as Leon's scheming son-in-law.

After many small film roles, O'Connell returned to Broadway, where he played the aging suitor of an old-maid schoolteacher in Picnic — a role he recreated in the 1956 film version, earning an Oscar nomination for it. Later, the weary-looking O'Connell was often invited to play forty-something losers and alcoholics; in the latter capacity he appeared as James Stewart's drunken mentor lawyer in Anatomy of a Murder (1959), and the result brought him another Oscar nomination. In 1962 O'Connell played the father of Elvis Presley's character in the film Follow That Dream, and in 1964 in Presley's film Kissin' Cousins.

O'Connell continued to appear in selected character roles on both television and film in the 1960s, but avoided a regular television series, waiting until he was guaranteed first billing. He appeared as Joseph Baylor in the 1964 episode "A Little Anger Is a Good Thing" of ABC's medical drama about psychiatry, Breaking Point. The actor agreed to play a man who discovers that his 99-year-old father has been frozen in an iceberg in the 1967 sitcom The Second Hundred Years, believing that by agreement with the producers his name would be first in the credits. Instead, first billing went to newcomer Monte Markham in the dual role of O'Connell's father and his son. O'Connell took the demotion to second billing as well as he could, but never again trusted the word of any Hollywood executive.