Furnace Run is a tributary of Shamokin Creek in Northumberland County, Pennsylvania, in the United States.

It is approximately 1.0 mile (1.6 km) long and flows through Coal Township and Shamokin.

It is impaired by sedimentation and siltation from urban runoff and storm sewers, but is not impacted by mine drainage.

Furnace Run begins in a small lake in Coal Township, in the census-designated place of Fairview-Ferndale.

It flows east-northeast for its entire length, almost immediately entering the census-designated place of Edgewood.

[1] Furnace Run joins Shamokin Creek 21.54 miles (34.67 km) upstream of its mouth.

However, in the 1950s, it was diverted into underground mines, reducing the stream's ability to carry away waste in its channel.

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

Henry Myers constructed an iron furnace on the stream in 1825 on land purchased from Solomon Dunkelberger.