His other Broadway credits included Of Thee I Sing (1952), Sundown Beach (1948), On Whitman Avenue (1946), Truckline Cafe (1946), Brighten the Corner (1945), Mrs. January and Mr. X (1944), Apology (1943), and The Russian People (1942).

[4] In 1955, he appeared on television in episodes of Medic and Alfred Hitchcock Presents as well as such feature films as Chief Crazy Horse, Seven Angry Men, and The Court-Martial of Billy Mitchell.

From 1956 to 1970, Simon appeared in Broken Arrow, Disneyland, Dick Powell's Zane Grey Theater, Laramie, Black Saddle, Law of the Plainsman, Johnny Ringo, Cheyenne, and The Dakotas, Wichita Town, The Man From Blackhawk, The Texan, Tombstone Territory, Tate, and Shotgun Slade, Stagecoach West, Bat Masterson, Lawman, Klondike, and Frontier Circus, Have Gun - Will Travel, Wagon Train, The Legend of Jesse James, The Road West, Gunsmoke ("Cheap Labor"-S2E32, "Potato Road"-S3E5, “Father’s Love” - S9E24 & "The Mission" - S12E4), Laredo, The Virginian, Bonanza, and The Guns of Will Sonnett.

[5]: 923  He also appeared in such programs as Crusader, Route 66, Dante, The DuPont Show with June Allyson, Johnny Midnight, Straightaway, The Roaring 20s, Sea Hunt and State Trooper.

[citation needed] In the controversial 1962 episode "The Benefactor" of the legal drama The Defenders, Simon played an unrepentant abortion care provider who uses his trial to argue for a change in the law.

[citation needed] Simon portrayed Frank Stephens on Bewitched[5]: 96-97  and Everett McPherson on Nancy,[5]: 741  He also appeared in other sitcoms, such as Ichabod and Me, McHale's Navy, Mrs. G. Goes to College, Get Smart, and The Andy Griffith Show.

[citation needed] He appeared in A New Kind of Love (1963) starring Paul Newman and Joanne Woodward, as "Cervantes" in The Reluctant Astronaut (1967), and as a doctor in Private Duty Nurses (1971).

[citation needed] He had a recurring role as Captain Rudy Olsen on The Streets of San Francisco and portrayed J. Jonah Jameson on The Amazing Spider-Man (1978-1979).