John Gerard O'Hara (born 18 April 1981, Dublin) is an Irish association football player, currently assistant coach for the George Mason University soccer teams.

O'Hara was invited to the MLS Combine after his final season at GMU but signed with Sligo Rovers in his native Ireland for the 2005 campaign.

He helped guide Rovers to the Eircom Irish First Division crown and promotion to the Premier League in his first season.

O'Hara has previously played in the United Soccer Leagues as a member of the Richmond Kickers Future PDL side where he earned 2003 Goalkeeper of the Year honors and All PDL League Team honors.

O'Hara signed with the Wilmington Hammerheads of the USL Second Division in the spring of 2008 where he served as captain of the team O'Hara finished the 2008 season with DC United of the MLS, seeing time with their Reserve team.