Robert L. Cormack was born in Cuthbert, Randolph County, Georgia on April 6, 1935. He graduated from Terrell County High School in Dawson, Georgia in June of 1953. Cormack joined the US Navy in July of 1953 where he was promoted to Petty Officer 2nd Class. He left the Navy in July of 1957 and entered the University of Georgia on the GI Bill. After 2 years at Georgia he transferred to Chouinard Art School in Los Angeles, California between 1959 and 1962.

After traveling around for a few years he returned to school, studying at Cal State Northridge where he received his MA in 1970. He then worked for CalArts (California Institute of the Arts), first as a janitor and then assisting with the Faculty Shows between 1970 and 1974. As his family grew he went to work the the US Post Office as a letter carrier, earning a union salary with benefits. Cormack retired from the post office in 1995 and has worked as an artist again since.

He exhibited throughout L.A. County between 1960 and 1975 and, after moving to Northern California, has exhibited locally on occasion.

Robert L. Cormack currently lives in Santa Rosa, California.