Born in 1896 in San Francisco, Juliet Gregory graduated from San Diego State College in 1919, obtaining an elementary teaching certificate. For the next two years, Gregory stayed in the San Diego area to teach before becoming a social worker for Young Women's Christian Association (YWCA) until 1925. In that same year she married Horace W. Gregory, who was a Director of Highways in Boise, Idaho. She and her husband moved to Helena, Montana, in 1932, and three years later they moved to Missoula, Montana. After 22 years of being a housewife, Gregory moved back into the work force, becoming Missoula's first and only woman mayor from 1947 until 1949. After her unsuccessful reelection bid in 1949, Gregory decided to return to school at Montana State University in Missoula. She received her B.A. in sociology and anthropology in 1955. While studying for her B.A., Gregory returned to teaching elementary school, which she did until her retirement in 1962.
Gregory remained active in both personal and civic duties throughout her life. She was active in many different clubs and organizations. She was president of the Missoula County Republican Women's Club, which allowed her to serve on the Montana Republican delegation for the 1964 Republican National Convention. Gregory was invited in 1955 to serve on the Defense Advisory Committee on Women in the Services (DACOWITS) by President Dwight Eisenhower. Gregory was also involved in various other organizations including the Missoula Chamber of Commerce, Community Chest Board, Parent Teachers' Association, Daughters of the American Revolution, Business and Professional Women, American Association of University Women, Y.W.C.A., Missoula Women's Club, Missoula Women's Civic Council, League of Women Voters, Red Cross Board -World War II, Episcopal Church and St. Hilda's Guild, Wives of Phi Kappa Psi, Sigma Alpha Epsilon Minerva Club, Rotary Club Wives, Montana Education Association, Missoula Teachers' Association, and the Missoula Cemetery Board. She died in 1990.
From the guide to the Juliet Gregory papers, 1916-1991, (Maureen and Mike Mansfield Library Archives and Special Collections)