Paramount
Kellaway made West Point Widow (1941) at Paramount and signed a contract with that studio. He did A Very Young Lady (1941) at Fox, Burma Convoy (1941), New York Town (1941), Birth of the Blues (1941), and Appointment for Love (1941) at Universal.
At Paramount, he was in The Night of January 16th (1941), Bahama Passage (1941), The Lady Has Plans (1941), and Take a Letter, Darling (1941). Fox borrowed him for Small Town Deb (1941), then he returned to Paramount for Are Husbands Necessary? (1942), and Night in New Orleans (1942).
Kellaway had a strong part in I Married a Witch (1942) as Veronica Lake's character's father. He followed it with My Heart Belongs to Daddy (1942).
He had cameos in Star Spangled Rhythm (1943) and Forever and a Day (1943), and was in The Crystal Ball (1943), and It Ain't Hay (1943).
Paramount gave him the starring role in The Good Fellows (1943). He returned to supporting parts for Frenchman's Creek (1944). He was going to do Out of This World on Broadway when he was offered the role of Edward VII in Mrs. Parkington (1944) at Metro-Goldwyn-Mayer.
Back at Paramount, he was in And Now Tomorrow (1944), Practically Yours (1944), and Love Letters (1945), the latter also starring Kellaway's one-time Australian co-star Ann Richards.
In Kitty (1945), he was as painter Thomas Gainsborough. MGM borrowed him to play the ill-fated husband of Lana Turner's character in The Postman Always Rings Twice (1946), a supporting role in Easy to Wed (1946) and the villain in The Cockeyed Miracle (1946).
In early 1946, he was earning $1,500 a week but said he was considering returning to Australia to run a film studio because he was sick of playing small roles.
Back at Paramount he was in Monsieur Beaucaire (1946), Variety Girl (1947), and Unconquered (1947).
Kellaway was borrowed by Warners for Always Together (1947) then he went to 20th Century Fox for The Luck of the Irish (1948), which earned him an Oscar nomination.
Kellaway went to RKO for Joan of Arc (1948).
Kellaway was in The Decision of Christopher Blake (1948), Portrait of Jennie (1948), Down to the Sea in Ships (1949), The Reformer and the Redhead (1950), back at MGM.
In 1950, it was announced James Hilton was writing a script as a vehicle for Kellaway, Roof of the World, based on the actor's time in India. It was not made.
He was in Harvey (1950), Kim (1950), Katie Did It (1951), Francis Goes to the Races (1951), Half Angel (1951), and The Highwayman (1951).
He returned to Paramount for Thunder in the East (1952) and was in Just Across the Street (1952), My Wife's Best Friend (1952), Young Bess (1953), The Beast from 20,000 Fathoms (1953), Cruisin' Down the River (1953), and Paris Model (1953).
In 1954, he became an American citizen (his nationality had been South African).
At MGM he was in The Prodigal (1955) and Interrupted Melody (1955), playing an Australian in the latter (the father of Marjorie Lawrence). He did two with Jeff Chandler, Female on the Beach (1955) and The Toy Tiger (1956), and was billed second (to Ethel Barrymore) in Johnny Trouble (1957).
He worked regularly on television in shows like Lux Video Theatre, The Ford Television Theatre, Schlitz Playhouse, Cavalcade of America, Schlitz Playhouse, Playhouse 90, Studio One in Hollywood, Matinee Theatre, and Crossroads.
Kellaway was in The Proud Rebel (1958), The Shaggy Dog (1959), and The Private Lives of Adam and Eve (1960).
He appeared on Broadway in Greenwillow (1960) which had a short run.
