Cox was born as Ida Prather in Toccoa, Stephens County, Georgia, and grew up in Cedartown, Georgia. She toured with traveling minstrel shows, often appearing in blackface in to the 1910s; she married fellow minstrel performer Adler Cox.
From 1923 through 1929 Cox made numerous recordings for Paramount Records. In 1939 she returned to the recording studio for Vocalion Records. In the 1940s she recorded for Okeh and Columbia, worked with Coleman Hawkins in the 1950s, and made her last recordings for Riverside in the early 1960s.
Ida Cox died in Knoxville, Tennessee.