Riles was born poor and Black in Louisiana. He was orphaned at an early age, but was fostered by family friends. He worked his way through school and university.
After some years of teaching and as a school principal he joined the California State Department of Education in 1958 as a consultant, its first ever African-American professional employee. In 1970 he was elected state superintendent of schools and was reelected in 1974 and 1978. He left office in 1983 to form an educational consulting firm, Wilson Riles and Associates, Inc.
He was the first African-American ever elected to a state-wide office in California and the first elected African-American state superintendent of schools.