Ashelman Run is a tributary of Coles Creek in Columbia County, Pennsylvania, in the United States.

Ashelman Run begins in a large pond in Sugarloaf Township, on the southern base of Central Mountain.

[1] Ashelman Run joins Coles Creek 3.54 miles (5.70 km) upstream of its mouth.

The stream also passes through a small patch of fill near its headwaters, where it crosses Pennsylvania Route 118.

The Wisconsinan Till Moraine occurs a short distance north of its headwaters.

[4] Ashelman Run was entered into the Geographic Names Information System on August 2, 1979.

[5] Wild trout naturally reproduce in Ashelman Run between its headwaters and its mouth.