Born in Rotherham, Ollie was a product of the Millers' youth system, making his professional debut for the Yorkshire side in Rotherham's 3-1 League Two victory over Torquay United on 7th May 2011. To further his experience, he also had loan periods at Sheffield, Buxton and Stalybridge Celtic before leaving Rotherham in 2012.
Between 2012 and 2013, Ollie had short-term agreements at Gainsborough Trinity, Scarborough Athletic and FC United of Manchester before signing for Chesterfield in 2013. He made league 81 appearances, scoring 9 goals over 3 seasons with the Spireites, helping them to the 2013-14 League Two title and a runners-up finish in the 2014 Football League Trophy. He also won the Football League Young Player of the Month award for November 2013 after scoring 4 goals in 6 matches.
Whilst recovering from an injury, he had a brief loan spell at Northampton Town in 2014. Ollie departed Chesterfield permanently in 2016, signing for League One Oldham Athletic, for whom he made 51 appearances.
Ollie joined Tranmere Rovers on loan from Oldham on 18th November 2017, making his debut for the Prenton Park outfit in an away match at Gateshead. Between November 2017 and January 2018, Banks represented the Super White Army 8 times, scoring once in the 5-2 away defeat at AFC Fylde.
Having impressed with Rovers, Banks returned to Oldham before quickly joining League Two Swindon Town on loan for the rest of the 2017-18 campaign. Just as at Tranmere, Banks became a key figure for the Robins, making 19 appearances and scoring 3 goals as the County Ground side fell just short of the play-off places.
Upon Oldham's relegation to League Two, Banks was released and was immediately secured to a 2-year contract by newly-promoted Tranmere, manager Micky Mellon bringing Ollie back to Prenton Park for the Club's return to the EFL.
Ollie had a great impact upon his Prenton Park return. He scored 4 goals in 39 appearances, including the Club's first-ever goal awarded via goal-line technology in the 1-0 play-off semi-final first-leg victory over Forest Green Rovers on 10th May 2019. Banks played in the 2018-19 League Two Play-off Final victory over Newport County as Rovers secured a second successive promotion at Wembley.
Interesting Fact: Ollie is the son of former professional footballer Ian Banks, who made 590 Football League appearances, scoring 87 goals for clubs including Barnsley, Leicester City, Huddersfield Town and West Bromwich Albion.