Johnson was born in Atlanta, Georgia, to parents of African American, Native American, and English descent. She graduated from Atlanta University Normal College and studied music at the Oberlin Conservatory and the Cleveland College of Music. After graduation, she taught and worked as an assistant principal. In 1910 she moved with her husband to Washington, D.C. When her husband died in 1925, Johnson supported her two sons by working temporary jobs until she was hired by the Department of Labor. Johnson’s house came to be known as site of the S Street Salon, was an important meeting place for writers of the Harlem Renaissance in Washington, D.C.