Sigourney Thayer (March 24, 1896 – November 2, 1944) was an American theatrical producer, World War I aviator, and poet.

He wrote regular poetry for the Atlantic Monthly, and his poem, "The Dead" has appeared in numerous World War I anthologies.

He produced Last Night of Don Juan: The Pilgrimage (1925), Beau-Strings (1926), Damn the Tears (1927), Bridal Wise (1932), and Keeper of the Keys (1933).

She filed for divorce in February 1935, and killed herself at the Dead Horse Ranch near Las Vegas, New Mexico, on May 24, 1935.

[10][11] She was a society columnist for the New York Journal, and wrote under the house pseudonym "Madame Flutterby", covering the Lindbergh kidnapping.