Ken Beamish started his career with Fourth Division Tranmere Rovers in 1966 under the management of Dave Russell. Rovers missed out on promotion at the end of the 1965-66 season after finishing behind fourth place Colchester United on goal average. Promotion was achieved in 1966-67.
In March 1972, Ken switched to league rivals Brighton & Hove Albion where he enjoyed a successful start to his Brighton career, as the Seagulls won promotion as Third Division runners-up in 1971–72. However the club struggled in the Second Division and finished in last place in 1972-73, Manager Pat Saward was replaced by Brian Clough but the 1973-74 campaign was also difficult, as Brighton avoided their second successive relegation by eight points. Ken had played 99 matches for the Seagulls scoring 28 goals.
Ken was signed by Blackburn Rovers for a £25,000 fee in May 1974. He soon built a good understanding with strike partner Don Martin. The 1974-75 season was successful, as Blackburn were promoted to the Second Division as champions of the Third Division, Rovers finished mid-table in 1975-76 under the stewardship of Jim Smith. A popular player, fans would chant “Beamo, Beamo” years after he left Ewood Park.
Ken joined Third Division Port Vale for £12,000 in September 1976 and went straight into the first team. He became the club’s top scorer in the 1976-77 season. Ken moved to Third Division Bury in September 1978. He helped Bury avoid relegation in 1978-79, as he scored 20 goals in 49 league games for the club before he returned to Tranmere Rovers in November 1979.
Throughout his career Ken played 555 matches in the Football League, scoring 159 goals.