Callum Thomas Ainley (born 2 November 1997) is an English professional footballer who plays as a midfielder for EFL League Two side Grimsby Town.

Ainley began his career in Crewe Alexandra's academy and made his professional debut, aged 17, on 5 September 2015 in a 3–1 defeat against Swindon Town.

[6] Two days after his 20th birthday, on 4 November 2017, he scored the 89th-minute winner in a 2–1 victory over Rotherham United in the FA Cup first round at Gresty Road.

After suffering a shoulder injury during a League Two game against Mansfield Town at Gresty Road on 24 September 2022, Ainley required surgery and was ruled out for around three months.

"[20] After leaving Crewe Alexandra in the summer of 2023, Ainley signed for League Two side Grimsby Town on a one-year deal in September 2023.