J. J. Barnes (born James Jay Barnes, November 30, 1943, Detroit, Michigan) is an American R&B singer.

He first recorded in 1960. His early releases including "Just One More Time" and "Please Let Me In", on the record labels Mickay and Ric-Tic, had relatively little success, but were subsequently picked up as Northern soul favorites. He also covered The Beatles' "Day Tripper"”, before moving for a short period to Motown.