Greg Nixon (born September 12, 1981) is an American sprinter who specialises in the 400 meters.

Nixon attended and competed for Howard Payne University in both sprinting and football.

At the 2008 IAAF World Indoor Championships, Nixon finished third in his 400 m heat with a time of 47.64.

[2] At the 2010 IAAF World Indoor Championships, Nixon won a second gold medal in the 4 × 400 m relay.

At the 2011 USA Championships, Nixon reached the podium again to make the 2011 World Champion team.