Cook began her stage career as a vaudeville performer. She appeared in Broadway musicals, in
The Passing Show of 1919,
The Midnight Rounders of 1921,
Blossom Time (1921–1923), and
The Passing Show of 1924. She also sang on radio broadcasts, and played herself in one short silent film,
Starland Review No. 4 (1922). She was considered a stage beauty, Cook returned to vaudeville in 1923, and starred in
Gus Edwards'
Sunbonnet Sue revue. "Olga Cook is the queen bee of vaudeville singers," noted Washington Daily News in 1923. "No perching and twittering; no fussing and fooling. She strides to the stage, opens her mouth, and beautiful sounds come out. She is a thoro, banging hit, and deservedly." She appeared in
The Student Prince in Chicago in 1925, Cook's rest was short-lived. In 1927, she and pianist Eric Zardo toured together, and performed at a midnight benefit in New York City for Mississippi flood victims. In 1928, she starred as
Barbara Fritchie in an operetta called
My Maryland, when it was produced in Philadelphia, New York, and Hartford. In 1934, she sang at a
Daughters of the American Revolution memorial service at a battlefield on
Mackinac Island. ==.Personal life==