Robert Mills-Roberts was born in Penmachno, Wales, on 5th August 1862. He played in goal for Aberystwyth University before entering the teaching hospital at St Thomas in 1882.
Mills-Roberts played for Corinthians before signing for Preston North End in 1888. The first season of the Football League began in September, 1888. Mills-Roberts competed with James Trainer for the goalkeeping position. That season Preston North End won the championship without losing a single match.
Robert Mills-Roberts died in 1935.