Josephine Louise Miles was born on June 11, 1911, to Reginald Miles and Josephine Miles, a Chicago couple. When she was still an infant, Miles was diagnosed as having rheumatoid arthritis, a disease that plagued her all her life. When she was five, her father, who was in the insurance business, moved the family to Southern California, hoping that the climate there would be beneficial to his daughter’s condition. The family moved back to Evanston, Illinois, for a time, but Miles had identified California as her spiritual home. The family eventually settled down in Los Angeles, and Miles, after finishing at Los Angeles High School, attended the University of California, Los Angeles. After receiving her B.A. in 1932, she enrolled in graduate school at the University of California, Berkeley. She completed her M.A. in 1934 and her Ph.D. in 1938.
Although she had written poems since childhood, it was during her graduate school years that she first began to publish seriously and to gain recognition. Her first poems were published in an anthology, Trial Balances (1935), and this work earned for her two awards. Her first book, Lines at Intersection, appeared in 1939 and contains the best poems of her graduate school period.
In 1940, Miles began teaching at Berkeley as an instructor, and she remained there for the rest of her life. In 1947, she was the first woman to be tenured by Berkeley’s English department, and in 1952, she was made a full professor. Miles never married, devoting her life to teaching, research, and poetry; during her years at Berkeley, she published more than two dozen books in addition to numerous articles and reviews. She retired in 1978 and was given the status of distinguished professor emerita. She died in Berkeley of pneumonia on May 12, 1985.