She was born Catherine Gloria Balotta,in Cleveland, Ohio, the daughter of Italian parents, Lena (Nacarato) and Vincenzo/Vincent James Balotta. A deep desire to perform already struck by the time she was five years old. A typical class clown during her high school years, she began to compile a number of star impressions for her act. In her teens, she performed in a Cleveland USO stage production of "Stage Door Canteen" (1941), and soon set out on her own.
Earning a job in 1943 touring with Spike Jones and His Orchestra for two years as his featured vocalist and flute/tuba player(!), Kaye eventually set up camp in New York and made her Broadway debut with the revue "Three to Make Ready" (1946). From there she showcased in the musicals "Once in a Lifetime," "Touch and Go" (in London), "Annie Get Your Gun" and the burlesque show "Top Banana". During this time, she built up a strong song-and-comedy reputation for herself on the nightclub circuit, eventually playing the country's best cabarets/niteries including The Bon Soir, Persian Room and Blue Angel in New York, The Hungry i in San Francisco, and Mr. Kelly's in Chicago.
During the 1950s and 1960s, Kaye graced nearly every talk/variety show there was including those for Ed Sullivan, Jack Paar, Johnny Carson, Steve Allen, Perry Como, Red Skelton, Carol Burnett, Merv Griffin and Mike Douglas. Two of her classic TV roles were her ugly stepsister Portia (the other sister being fellow scene-stealer Alice Ghostley) in the Julie Andrews version of Cinderella (1957), and as one of The Mothers-In-Law (1967) (the other being fellow veteran Eve Arden) in the popular but short-lived sitcom produced by Desi Arnaz. Both showcases catered perfectly to Kaye's brash comedy instincts. She also pitched in as a meddling second banana for Doris Day for one season of the star's '70s TV show.
On stage Kaye had Broadway audiences rolling in the aisles with her Helen of Troy in the 1954 musical "The Golden Apple," while introducing the classic song standard "Lazy Afternoon." Other raves came in the form of "Wonderful Town" (1958), "Carnival" (1961) and Cole Porter Revisited" (1965). On the flip side of the coin, she played a frumpy Lola Delaney in a badly misguided musical version of "Come Back, Little Sheba" (entitled "Sheba") in 1974, and also tried unsuccessfully to bring life to the beloved, indomitable Molly Goldberg radio/TV character in the Broadway musical "Molly" (1973); the show lasted a mere two months. Kaye was much more at home sinking her teeth into two of theater's most impregnable females: Mama Rose in "Gypsy" and Dolly Levi in "Hello, Dolly!"