The Philadelphia Distanced Run is an annual half marathon road running event which takes place in Philadelphia, Pennsylvania in the United States on the third Sunday of September. The competition was established in 1978 as the Philadelphia Distance Run and was founded by Gene H. Martenson, and was held under this name until 2009. Starting in 2010 when Competitor Group Inc. bought the rights to the race, it has been part of the Rock 'n' Roll Marathon Series of running competitions. It is now a hybrid profit/non-profit model race.