[1] The daughter of a Winnipeg doctor, MacKenzie spent her childhood in Manitoba where she studied violin and attended the Sacred Heart School as a child.

She had at least two Canadian Broadcasting Corporation radio programs, Meet Gisèle, where she played hostess to Jack Benny, Clark Gable, Loretta Young, Fred Astaire, and James Stewart; and Gisele and Mr. Cable.

She took on the stage name MacKenzie and moved to Los Angeles, California in 1951 to replace The Andrews Sisters on CBS Radio's daily program, Club Fifteen, starring Bob Crosby, where she alternated as regular vocalist with Jo Stafford.

In an often-played clip, she and Benny perform a violin duet of "Getting to Know You", in which she breaks their synchronization several times to add some extra musical flourishes, to his mock irritation.

Finally, he breaks in with a lengthy (and stereotypically mediocre) flourish of his own, and evokes audience laughter with mock indignation: "Fool around with ME, sister!

She went on to star in her own short lived Saturday night NBC variety program, The Gisele MacKenzie Show, and hosted such guests as Benny, Boris Karloff, Ronald Reagan, Bobby Diamond, and folk singer Jimmie Rodgers; it was cancelled after twentysix weeks.

She expanded her acting credits in the 1990s, making guest appearances on television series including Murder, She Wrote, Boy Meets World, and MacGyver.