The Houston Marathon is an annual marathon held every January in Houston, Texas. With thousands of runners and spectators, it is the largest single day sporting event in the city. It is run concurrently with a half marathon and a 5 km (5000 metres) race. The 2007 race included the first-ever satellite running of the event, run simultaneously in Fallujah, Iraq.

The first marathon, run on December 30, 1972, featured 113 runners and a crowd of approximately 200 people. Today, as many as 15,000 take part in front of a far larger crowd of 200,000. The course has been repeatedly selected for many world-renowned road-racing competitions, including:

* The 2007 and 2008 USATF Men?s and Womens Half Marathon National Championship * The 2005 and 2006 USATF Men?s Half Marathon National Championship * The 1998 USATF Women?s Marathon Championship * The 1992 USATF Women?s Olympic Marathon Trials and * The 1979 USATF Men?s and Women?s Marathon Championship.

Along with the Dallas White Rock Marathon and the Austin Marathon, the Houston Marathon forms the middle leg of the Marathons of Texas, a series of winter marathons held approximately one month apart from each other from December through February in Texas.

George W. Bush did the Houston Marathon in 1993, finishing with the time of 3 hours, 44 minutes, 52 seconds.