| Banacek | 1972 | Albert Bates | TV Show |
| Emergency! | 1972 | Hoyt Herrold, Lee | TV Show |
| Kung Fu | 1972 | Davidson | TV Show |
| The Streets of San Francisco | 1972 | Mr. Morley, Off. Mel Shaffer | TV Show |
| Bandolero! | 1968 | Stoner | Movie |
| The Love Bug | 1968 | Driver (as Jack Mahoney) | Movie |
| Hawaii Five-O | 1968 | Coley Bennett | TV Show |
| Portrait of Violence | 1968 | | Movie |
| The Glory Stompers | 1967 | Smiley | Movie |
| Once Before I Die | 1966 | Major (uncredited) | Movie |
| Batman | 1966 | H.L. Hunter, Leo | TV Show |
| Tarzan | 1966 | Chambers, Hoby Wallington, The Colonel | TV Show |
| Runaway Girl | 1965 | Randy Minola | Movie |
| Daniel Boone | 1964 | O'Connor | TV Show |
| Intramuros | 1964 | Lt. Jim Sorenson | Movie |
| Moro Witch Doctor | 1964 | CIA Agent Jefferson Stark | Movie |
| Cimarron | 1964 | | Movie |
| Tarzan's Three Challenges | 1963 | Tarzan | Movie |
| California | 1963 | Don Michael O'Casey | Movie |
| Marine Battleground | 1963 | Nick Rawlins | Movie |
| Tarzan Goes to India | 1962 | Tarzan | Movie |
| Gunslinger | 1961 | Halsey Roland | TV Show |
| Three Blondes in His Life | 1961 | Duke Wallace | Movie |
| Tarzan the Magnificent | 1960 | Coy Banton | Movie |
| Simon Lash: The Black Book | 1960 | Simon Lash | TV Movie |
| Laramie | 1959 | Clay Jackson, Sam Willet | TV Show |
| Rawhide | 1959 | Captain Brian Donahoe, Vance | TV Show |
| A Time to Love and a Time to Die | 1958 | Immerman | Movie |
| The Last of the Fast Guns | 1958 | Brad Ellison | Movie |
| 77 Sunset Strip | 1958 | Barry James | TV Show |
| Yancy Derringer | 1958 | Yancy Derringer | TV Show |
| Money, Women and Guns | 1958 | 'Silver' Ward Hogan | Movie |
| Battle Hymn | 1957 | Maj. Frank Moore | Movie |
| Joe Dakota | 1957 | Joe Dakota | Movie |
| The Land Unknown | 1957 | Commander Alan Roberts | Movie |
| Wagon Train | 1957 | Dan Hogan | TV Show |
| Slim Carter | 1957 | Slim Carter aka Hughie Mack | Movie |
| Away All Boats | 1956 | Alvick | Movie |
| A Day of Fury | 1956 | Marshal Allan Burnett | Movie |
| Showdown at Abilene | 1956 | Jim Trask | Movie |
| I've Lived Before | 1956 | John Bolan, Lt. Peter Stevens | Movie |
| The Millionaire | 1955 | Vance Ludlow | TV Show |
| Gunfighters of the Northwest | 1954 | Sgt. Joe Ward (as Jack Mahoney) | Movie |
| Overland Pacific | 1954 | Ross Granger (as Jack Mahoney) | Movie |
| Knutzy Knights | 1954 | Cedric the Blacksmith (as Jacques O'Mahoney) | Short Film |
| Private Secretary | 1953 | Bradley Hunter | TV Show |
| The Loretta Young Show | 1953 | Dan O'Hara, Jim Vessey, Mike Elliott | TV Show |
| Death Valley Days | 1952 | Andy Prentis, Sal aka Swamper Ike | TV Show |
| Smoky Canyon | 1952 | Jack Mahoney (as Jack Mahoney) | Movie |
| The Kid from Broken Gun | 1952 | Jack Mahoney (as Jack Mahoney) | Movie |
| The Hawk of Wild River | 1952 | Jack Mahoney (as Jack Mahoney) | Movie |
| Junction City | 1952 | Jack Mahoney (as Jack Mahoney) | Movie |
| Laramie Mountains | 1952 | Swift Eagle (as Jack Mahoney) | Movie |
| The Rough, Tough West | 1952 | Big Jack Mahoney (as Jack Mahoney) | Movie |
| Santa Fe | 1951 | Crake (as Jock O'Mahoney) | Movie |
| The Texas Rangers | 1951 | Duke Fisher (as Jock O'Mahoney) | Movie |
| The Range Rider | 1951 | Curt Manning, Range Rider, The Range Rider | TV Show |
| The Lady and the Bandit | 1951 | Tavern Troublemaker (uncredited) | Movie |
| Pecos River | 1951 | Jack Mahoney (as Jack Mahoney) | Movie |
| Roar of the Iron Horse - Rail-Blazer of the Apache Trail | 1951 | Jim Grant (as Jock O'Mahoney) | Movie |
| The Nevadan | 1950 | Sandy (as Jock O'Mahoney) | Movie |
| Cody of the Pony Express | 1950 | Lt. Jim Archer (as Jock O'Mahomey) | Movie |
| Cow Town | 1950 | Tod Jeffreys (as Jock O'Mahoney) | Movie |
| David Harding, Counterspy | 1950 | Brown (uncredited) | Movie |
| Hoedown | 1950 | Stoney Rhodes (as Jock O'Mahoney) | Movie |
| The Kangaroo Kid | 1950 | Tex Kinnane (as Jock O'Mahoney) | Movie |
| Frontier Outpost | 1950 | Lieutenant Peck (uncredited) | Movie |
| Lightning Guns | 1950 | Sheriff Rob Saunders (as Jock O'Mahoney) | Movie |
| Punchy Cowpunchers | 1950 | Elmer (as Jock O'Mahoney) | Short Film |
| Texas Dynamo | 1950 | Bill Beck (as Jock O'Mahoney) | Movie |
| Jolson Sings Again | 1949 | | Movie |
| Bandits of El Dorado | 1949 | Tim Starling (uncredited) | Movie |
| Rim of the Canyon | 1949 | Pete Reagan (as Jock O'Mahoney) | Movie |
| The Doolins of Oklahoma | 1949 | Tulsa Jack Blake (as Jock O'Mahoney) | Movie |
| Fuelin' Around | 1949 | Guard (as Jacques O'Mahoney) | Short Film |
| The Blazing Trail | 1949 | Full-House Patterson (as Jock O'Mahoney) | Movie |
| Horsemen of the Sierras | 1949 | Bill Grant (as Jock O'Mahoney) | Movie |
| Renegades of the Sage | 1949 | Lt. Hunter (as Jock O'Mahoney) | Movie |
| Blazing Across the Pecos | 1948 | Reports Indian Raid (uncredited) | Movie |
| The Swordsman | 1948 | Clansman Messenger (uncredited) | Movie |
| Triple Threat | 1948 | Football Player (uncredited) | Movie |
| Squareheads of the Round Table | 1948 | Cedric the Blacksmith (as Jacques O'Mahoney) | Short Film |
| Smoky Mountain Melody | 1948 | Buckeye | Movie |
| Over the Santa Fe Trail | 1947 | Sheriff (uncredited) | Movie |
| Out West | 1947 | The Arizona Kid (as Jacques O'Mahoney) | Short Film |
| South of the Chisholm Trail | 1947 | Henchman (uncredited) | Movie |
| Swing the Western Way | 1947 | Chief Iron Stomach (uncredited) | Movie |
| The Stranger from Ponca City | 1947 | Henchman Tensleep (uncredited) | Movie |
| San Quentin | 1946 | Soldier (uncredited) | Movie |
| Son of the Guardsman | 1946 | Captain Kenley (uncredited) | Movie |
| The Fighting Frontiersman | 1946 | Henchman Waco (uncredited) | Movie |
