Herlihy, a talented individual, held a position analogous to Ed McMahon's on "The Tonight Show" prior to Johnny Carson's arrival in 1962, bringing McMahon along with him. Before Carson's tenure as host, Herlihy served as the announcer during Jack Paar's time as host of the show, succeeding Hugh Downs who had departed to host NBC's "Today" program.
As a handsome and charismatic individual, Herlihy was distinguished by his mellifluous voice, which he had honed through his earlier work on Perry Como's broadcasts, originally known as "The Chesterfield Supper Club". In addition, he had provided commentary for Universal newsreels during the 1940s and was a prominent radio announcer during the 1930s and 1940s.
Herlihy's extensive career in television spanned nearly 40 years, commencing in 1947, during which time he served as a most pleasant-mannered TV spokesman for the US cheesemaker Kraft Foods. Interestingly, his brother, Walter Herlihy, was also a TV announcer in the early days of television.