National Marathon is an annual marathon and half marathon held in Washington, D.C. It was established in 2006 as an annual event. It is organized by the Greater Washington Sports Alliance.

The 26.2 mile (42 km) course starts and finishes at the RFK Stadium (Robert F. Kennedy Memorial Stadium) and the number of participants was limited to 8,000 in 2008. The course for the first running of the race was in Washington, D.C. and Prince Georges County, Maryland, but altered in 2007 for the course to be run entirely within the District of Columbia. The 2008 race passes through 6 of the Districts 8 wards.

Among the beneficiaries of the marathon are the Boys & Girls Clubs (Boys and Girls Clubs of America) of Greater Washington, the Special Olympics District of Columbia, United For D.C., Fort Dupont Ice Arena, the Washington Tennis & Education Foundation and the Black History Invitational Swim Meet.

In 2007, the National Marathon was sponsored by Wirefly, an online cell phone retailer. In 2008, SunTrust Banks became the races primary sponsor.