Born in Mount Barker in regional South Australia, Barnes played his early football for West Broken Hill Football Club in the Barrier Ranges Football Association in far west New South Wales, winning the Kenwrick Medal for Best and Fairest player in the competition.
A rover, he was recruited by West Adelaide of the 1921 season and represented the South Australian interstate team that year for the first of eight times.
West Adelaide supporters carried Barnes shoulder high from the ground.
[1] In 1922 Barnes won the Magarey Medal for the Best and Fairest player in the league and played in West Adelaide's losing Grand Final team.
Robert Barnes finished with 59 games and 67 goals for West Adelaide.