The 31-year-old was off the pace this morning as he finished 17th in a time of 13:47.01
He missed out on the final by almost 16 seconds.
Boxing: Katie Taylor has advanced to the Olympic final after a 17-9 win over Mayzuna Chorieva of Tajikistan in the flyweight semi-final this afternoon.
She will fight in the final tomorrow at 1645.
O'Connor posted a fault-free round in the final round A of the individual jumping event. That score qualified O'Connor for the final round B.
He incurred a time penalty in that round, leaving him joint second with Gerco Schroeder of the Netherlands.
Schroder posted a fault free round in the jump off; however, O'Connor clipped the last jump, meaning the Kildare man had to settle for bronze.
Boxing: Paddy Barnes has become the first Irish boxer - and only the second Irish sportsperson - to win medals at separate Olympic Games after he beat India's Devendro Singh Laishram in their light flyweight quarter-final.
A win against the Indian fighter guarantees the Belfast fighter at least a bronze medal at this year’s Olympics.
Barnes won on a scoreline of 23-18 against a tricky opponent, who caused problems throughout.