With his deep rich speaking voice, Conrad was a highly accomplished and prolific radio performer. He served as the narrator and a frequent participant on the thrilling "Escape" series (beginning in 1947 on CBS Radio) and numerous other shows ("Jason and His Golden Fleece"; "Pete Kelly's Blues"), but his most impressive achievement was creating US Marshall Matt Dillon for the 11-year run of the celebrated Western series, "Gunsmoke" (CBS Radio, c. 1949-60). Conrad lobbied hard to snare the lead in the TV version but his balding pate, round and mustachioed face, and ample physique did not fit the TV producers' image of a Western hero. Nonetheless, to those who remember, his tough and world-weary delivery will always represent the true voice of Marshall Dillon. Conrad's authoritative tones made him a valuable voice performer even in the TV age. Fans of the various incarnations of "Rocky and Bullwinkle" will long treasure his urgent narration of their witty cartoon adventures. He also introduced many of producer Quinn Martin's TV productions, most notably "The Fugitive" (CBS, 1963-67). Conrad announced for many series over the decades including "The Invaders", "Wild Wild World of Animals", "Tales of the Unexpected" (which he also hosted), "Buck Rogers in the 25th Century" and "Manimal". He also narrated features such as "The Battle of the Bulge" (1965) and the much-maligned Bruce Willis movie, "Hudson Hawk" (1991).
As a producer-director under contract with Warner Bros. for 15 years, Conrad competently churned out a number of low to medium budget genre programmers. His feature directorial credits were mostly Westerns ("The Ride Back" 1957, "The Man From Galveston" 1964) and thrillers ("Brainstorm" 1965, "My Blood Runs Cold" 1965). Notably Conrad was the executive producer of "Countdown" (1968), a riveting drama about the space program that marked the studio-backed fiction feature debut of director Robert Altman. Before shifting to production, Conrad had made a name for himself as a Hollywood character man beginning with a memorable film debut as one of "The Killers" in Robert Siodmak's 1946 noir classic. His subsequent credits spanned various genres but he tended to gravitate toward shady character parts in film noir: "Body and Soul" (1947); "Sorry, Wrong Number" (1948); and "Cry Danger" (1951). Conrad was a far more frequent presence on TV, appearing in many guest shots, TV movies, pilots, and various series, generally crime dramas. He also helmed or oversaw numerous TV episodes in the late 50s and early 60s including, as a director, "Gunsmoke", "Naked City" and "Route 66".