Grace Montanez Davis was born in 1926 in Los Angeles and grew up in the community of Lincoln Heights. She attended several schools in Los Angeles, including Immaculate Heart College the University of California, Los Angeles, where she received an MS in microbiology in 1949. She became politically active in the early 1950s when she became involved with the Community Service Organization (CSO), a broad-based service organization founded in 1949 by Edward Roybal, Fred Ross, and Saul Alinsky. During this time, she taught citizenship and voter registration classes and was actively involved in Edward Roybal's campaigns for office. She is one of the founding members of the Mexican American Political Association and served on the Democratic Party Minority Committee of Los Angeles. In 1964 she became the administrative assistant to Congressman George E. Brown Jr. In this position she helped institute the Los Angeles anti-poverty programs developed by President Lyndon B. Johnson. A year later she joined the Economic and Youth Opportunity Agency as a program development specialist.



In 1967 Montanez Davis helped Julian Nava campaign for and win a seat on the Los Angeles Unified School District Board of Education. Nava was the first Latino to serve on the school board. From 1966 to 1973 Montanez Davis was a field representative in the U.S. Department of Labor's Los Angeles District Office, where she worked as a manpower development specialist. Then, in 1973, Montanez Davis was recruited by then Mayor Tom Bradley to become the director of human resources for the Office of the Mayor of the City of Los Angeles. In this capacity Montanez Davis administered grants awarded for the purpose of developing an administrative capacity for coordinating, planning, and evaluating human delivery systems in Los Angeles. In addition, she administered an ACTION grant that developed the City Volunteer Corps, which involved over 200 former Peace Corps and Vista volunteers in various community projects.



In August 1975 Montanez Davis was appointed deputy mayor of Los Angeles. She was the first Mexican American woman to fill this position. Her main responsibilities included the general management review of the thirty-six city departments and bureaus as well as the management and supervision of the federally funded programs located in the Office of the Mayor. As Deputy Mayor she developed the city's Department of Aging, the Department of Justice, an Office of Volunteers, and an Office for Youth. Montanez Davis was also extensively involved in community relations, representing the mayor at city and international functions and political and community events, particularly those within the Latino community.



Montanez Davis is recognized as an authority on employment, a champion of women's rights, and a diligent worker for the rights of children—especially the underprivileged. She was also a founding member of the Comision Femenil Mexicana based out of Los Angeles. She is a regular panelist at public forums and university seminars. She has been on the board of directors of MALDEF (The Mexican American Legal Defense and Educational Fund) and a member of the Federal Advisory Committee on Immigration and Naturalization. She has received numerous recognitions and awards for her service to the community, including the coveted Aztec Award from the Mexican American Opportunity Foundation.