Callum McNish was signed by Exeter City in July 2011 after his release by Southampton. After making just seven appearances for the Grecians he left to sign for Braintree.

Callum had played in the Saints academy system since the under-12s, and after signing as a trainee/scholar in 2008, made a solitary first-team appearance for Southampton in April 2010. Released by Southampton in May 2011 Callum had impressed in pre-season games and signed for Exeter on a one-year deal.    

He made his Grecians’ debut in the League Cup against Yeovil Town on 9 August 2011 and played twice more that month including a substitute appearance against Liverpool in the League Cup. Subsequently Callum played twice in November and once in each of March and April to conclude his seven-game stay with City. He was then released in May 2012.

Callum signed for Braintree in July 2012 but soon returned to his Oxford roots to play for Basingstoke Town, Oxford City, North Leigh and Didcot Town before moving back to North Leigh for whom he now appeared more often than any other team. In 2022/23 he was reported as playing for Ardley United in the Spartan South Midlands League.