Jarrow, County Durham born left winger George Keenlyside began his football career with Jarrow Royal Oak in 1904 and played for Jarrow Park Villa in 1905 and Jarrow Croft in 1906. He spent 1908-09 on the books as an amateur at Sunderland without making their first team, and played for both Jarrow and Dinnington Main Colliery Welfare in 1910 before joining Scottish League club Partick Thistle later the same year.
He spent a year in Scotland before returning to Jarrow Croft, but after the First World War he signed for Second Division South Shields in May 1919, making his Football League debut at Fulham in August 1919 already aged 30. He scored 12 goals in 105 appearances for South Shields over the next four seasons, playing most of their games in his final season at the club, before joining Hartlepools United in June 1923. A single season at Victoria Park saw him score twice in 27 games before he returned to non league football with Chester-le-Street in 1924, and then with Jarrow in 1925, his final club before his eventual retirement.