|Date of birth||24 March 1947|
|Place of birth||Bow, London, England|
|1962–67||West Ham United||3||(0)|
|* Senior club appearances and goals counted for the domestic league only.
Mackleworth joined West Ham United in 1962 as an apprentice. He played in West Ham's Youth Cup winning side of 1963 making his first-team debut in December 1966 in a 4-0 home win against Blackpool. Serving as understudy to regular goalkeeper, Jim Standen, he made only three appearances; his last being in a famous Manchester United 6-1 victory at Upton Park in which Manchester United won the 1966-67 Football League trophy. He left West Ham in November 1967 and joined Leicester City. Mackleworth failed to make an impact at Leicester and was understudy to Peter Shilton. Making only six appearances he joined Kettering Town.
- Barham, Albert (18 November 2005). "Manchester United take championship home to Old Trafford". www.guardian.co.uk. London. Retrieved 27 August 2011.
- "Colin Mackleworth". www.westhamstats.info. Retrieved 29 August 2011.
- Hogg, Tony (1995). West Ham United Who's Who. London: Independent UK Sports publications. p. 120. ISBN 1-899429-01-8.
- "Where are they now?". www.where-are-they-now.co.uk. Retrieved 29 August 2011.