Rock Run is a tributary of Martins Creek in Lower Makefield Township in Bucks County, Pennsylvania in the United States.

Rock Run was entered into the Geographic Names Information System of the U.S. Geological Survey on 2 August 1979 as identification number 1185276.

[2] Rock Run rises near Big Oak Road and Stony Hill Road in the southern portion of Lower Makefield Township at an elevation of approximately 150 feet (46 m) and is generally east oriented until river mile 2.87 where it makes a 90° turn to the right flowing south as it receives a tributary from the left.

[3] Rock Run rises in the Felsic Gneiss formation laid during the Precambrian, light buff to pink and medium to fine grained rock, mineralogy includes quartz, microcline, pyroxene, and biotite.

As it flows east, it runs into the Pensauken and Bridgeton Formations laid down during the Tertiary period, yellow to reddish brown feldspathic quartz sand, coarse gravel, and boulder.