Ojo was an outstanding school sportsman at Dartford Grammar School in Kent where he captained the 1st XV and excelled at athletics. His student success saw him representing Kent and London & South-East Schools at both U16 and U18 levels.

Topsy's athletic abilities helped him to an equally successful start in senior rugby. After joining the London Irish Academy in July 2003, he made his first team debut against Bristol in September 2005. He has since gone on to become an established member of a talented London Irish backline, making 102 senior appearances and scoring 40 tries; among the most memorable of which were his two tries against Toulouse in the Heineken Cup semi-final at Twickenham in 2008.

A member of the 2006 Grand Slam winning England U21 squad, the elusive and pacey winger played in four of England's five matches, notching up a record four tries in their 48-3 victory over Italy.

Later that same year he played in every minute of the team's IRB U21 World Championship campaign, as part of a backline that contained Irish teammate Ryan Lamb. Topsy made his full international debut on England's 2008 summer tour to New Zealand, scoring two tries on his debut in the first Test. He retained his starting berth in the second match although he was powerless to prevent England going down to the home side in both games of the two-Test series.

A string of injuries restricted him to just seven starts in the 2009/10 season, but Ojo selflessly gave up a lot of his time to charity and community work, and was duly awarded the London Irish Community Player of the Season in 2010.