Dennis Day, known as "America's Favorite Irish Tenor", hosted his own radio and TV shows, but is probably best known for his role on The Jack Benny Program. He played himself, a "boy" singer and supporting actor on this show-within-a-show. While the character he played was that of a gentle, sweet, shy, trusting, and naive boy singer, a character he played throughout his career, the audience laughed with him, rather than at him. It was this very portrayal that got him many laughs as he would frequently show that he wasn't quite as naive as he came across. Jack Benny, who was generous as the star of the show, frequently gave his supporting cast the chance to get laughs at his expense and Dennis got his share, seemingly driving Jack to distraction through his sweet, naive, trusting nature. Dennis, a supporting character who had a long association with Jack Benny, was a great foil for Jack to play off. The association with Jack Benny began in 1939, when he was introduced as a "boy singer" on the Benny radio show. His first song was "Goodnight My Beautiful". The association lasted until Benny's death in 1974.

While he appeared as a supporting player on The Jack Benny Program, he also starred on his own radio show, "A Day in the Life of Dennis Day" (1946-1952). It became a running joke on the Benny show with Dennis rubbing Jack's nose in the fact that Dennis had two shows and Jack only one. From 1952-1954 Dennis also starred on his own TV show, "The Dennis Day Show" (aka The RCA Victor Show). He made many appearances as a singer and actor and voiced multiple characters for animated programs such as the Disney feature "Melody Time".

While not a top star, Dennis became a familiar and welcome radio and TV fixture during the 50's and 60's. Dennis Day was born Owen Patrick McNulty, May 21, 1918, in The Bronx, NY. Dennis served as a lieutenant in the US Navy during WWII. In 1948, he married Peggy Almquist; the marriage lasted until his death from Lou Gehrig's disease in 1988. The couple had ten children.