Ojo played his first Eredivisie match for PSV on 5 May 2009 against Willem II. He made five appearances for PSV in the Europa League, including two in the qualifying rounds.
On 18 July 2017, Ojo signed a three-year contract with Scunthorpe United. He made his competitive debut for the club in the season-opening match against AFC Wimbledon, which ended in a 1–1 draw at Glanford Park. His first goal for Scunthorpe came on 7 October 2017, in the 2–1 loss to Wigan Athletic.
Ojo believed that he could leave Scunthorpe on a free transfer after they were relegated to EFL League Two, but the proposed move stalled after Scunthorpe disputed whether Ojo could do this. Later in the summer, Scunthorpe accepted offers of £125,000 from Hibernian and Aberdeen. Ojo moved to Aberdeen, signing a three-year contract with the club.