His time of 20.69 was not good enough to see him qualify for the semi-finals as a fastest loser.
This is his second Olympics, having finished fifth in the 200m semi-finals in Beijing in 2008. His personal best over this distance is 20.30.
Athletics: After a disappointing 15th-place finish in the 10,000m on Friday, Fionnuala Britton has missed the cut for the 5,000m final.
Britton finished 21st, with the top five from two heats, and five fastest losers making the final.
Triathlon: The first Irishman to compete in the Olympic Triathlon, Gavin Noble finished 23rd in the event
He finished over three minutes behind the winner - Alistair Brownlee.
Sailing: Ger Owens and Scott Flanigan have finished 16th in race 9 of the men's 470 class. They move up to 25th in the overall rankings as a result.
The crew then finished fifth in race 10. That result leaves them 23rd overall, meaning they will not be one of the ten crews to contest the medal race.
Athletics: Derval O’Rourke made a sensational start to her 100m hurdles semi-final, but failed to qualify for the final after fading badly in the latter stages of the race to finish fifth behind Australia’s Sally Pearson in 12.91.
Boxing: Irish flyweight Michael Conlan is guaranteed at least is a bronze medal at London 2012 after progressing to the semi-finals of the division after recording a 22-18 win against France’s Nordine Oubaali. The 20-year-old will face Robeisy Ramirez Carranza on Friday afternoon after the classy Cuban saw off Great Britain’s Andrew Selby 16-11.