Myrtle Foster Cook (April 17, 1870 – August 31, 1951) was a Canadian-born American teacher, political activist, and clubwoman.

Myrtle Foster was born in Amherstburg, Ontario and raised in Monroe, Michigan, the daughter of James William Foster and Elizabeth Butler Foster.^[1] Both of her grandfathers escaped slavery in the United States, assisted by the Underground Railroad, and settled in Canada. Her father had a fruit and dairy farm in Monroe, and her sisters ran a candy business. She graduated from the University of Michigan.^[2][3]

Foster was a church organist and Sunday school teacher in her youth in Michigan. She was teaching at a normal school in Frankfort, Kentucky^[1] when she met her first husband, a doctor. She moved with him to Muskogee, Oklahoma, where she taught school, started a club, organized a lecture series, and raised funds to build a hospital.^[2][4]

Foster moved to Kansas City, Missouri in 1916. She was head of the English department at Lincoln High School, and met her second husband, a fellow teacher. The Cooks established a savings and loan association for African Americans. Myrtle Foster Cook was national chair of the NAACP's legal defense fund.^[5][6] She was a leader in the Kansas City chapters of the YWCA and the National Association of Colored Women (NACW). She was editor-manager of the NACW's National Notes from 1922 to 1926,^[7][8] and chaired the NACW's history department later in the 1920s,^[9] when she spoke on a conference panel with Carter G. Woodson, Sallie Wyatt Stewart, and Arsania Williams.^[10] In 1934 she was elected president of the NACW's Central District.^[11]

Cook organized to create the Jackson County Home for Negro Boys, and was a leader of the Women's League of Kansas City. She was appointed by governors Sam Aaron Baker and Arthur M. Hyde to the Missouri Negro Educational and Industrial Commission (MNEIC).^[1][3][12] She was active in suffrage work, and in Republican Party politics after the vote was won.^[7] She held various leadership roles in the 1920 and 1924 election cycles, and in 1928, Cook was named to the National Republican Executive Committee,^[2][13] working with Addie Waites Hunton on the Hoover campaign.^[14]

Myrtle Foster married twice. Her first husband was Dr. Louis G. Dodd. They married in 1900, and he died in 1911.^[4] Her second husband was Hugh Oliver Cook, who was principal of Lincoln High School from 1921 to 1944.^[15] They married in 1920, and she became stepmother to his young sons. The Cooks moved to Los Angeles in 1944, and Hugh O. Cook died there in 1949.^[16][17] She died in Los Angeles in 1951, aged 81 years.^[18]