Connor was born Katherine Grant Campbell Connor in Vancouver, B.C., on December 20th, 1925. Her family moved to Los Angeles in 1938, and Kaye, at age 12, immediately found work as child actress Jane Withers' stand-in.

While working in this capacity, and attending high school, she took violin lessons from impresario Peter Meremblum and appeared (uncredited) as a member of the Meremblum Junior Symphony in the movie "They Shall Have Music."

Because of her excellent work as Withers' stand-in, Paramount gave her a substantial role in the 1940 movie "There's Magic in Music," which was supposed to be a springboard for her film career. But most of the attention went to a previously unknown 13 year old pianist named Dolly Loehr, whose delicate beauty, charisma, and natural acting talent caught the eye of the film moguls. Loehr went on to a career as ingenue Diana Lynn.

While an accomplished violinist, Connor's true talent was singing. She moved to New York in 1946 and gravitated to the theatre, appearing in several musicals as a lyric (coloratura) soprano. She met her future husband, baritone George Britton, during this time, and they married in 1947, eventually having three children. Kaye continued to appear on stage in the United States, Britain, and Canada throughout the 1950s.

When they retired from the stage, Kaye worked in the travel industry, eventually opening her own highly successful travel agency.