Right back Robert Barr began his football career with junior clubs Kelburne and Park Royal, playing Army football when serving with The Black Watch, from where he joined Scottish First Division club Third Lanark in 1896. He was an important player for Third Lanark towards the end of the 19th century through the first decade of the 20th century.
He won The Glasgow Cup in 1903-04, beating Celtic in a replay. The same season Third Lanark won The Scottish League Championship for the only time in their history, Barr playing 24 of the 26 matches in the successful campaign, forming a solid partnership with William McIntosh in defence, which proved an important basis of the success.
He then featured as The Hi Hi won The Scottish Cup for the second (and final) time in their history as they beat Rangers in a replay in the 1905 Final, also playing in their Scottish Cup Final defeat to Heart of Midlothian in 1906, the year in which he received a benefit match against Queen’s Park. He also represented The Glasgow F.A. that October in their annual match with Sheffield. The next year he again won The Glasgow Cup with Third Lanark, and in his career he was also twice a runner up. He also twice won The Glasgow Merchants Charity Cup twice and was once a runner up.
In 1910 he joined Abercorn after a single goal in 239 appearances for The Warriors and over 300 matches in all competitions, and played 6 matches during 1910-11 before his retirement.