Tub Run is a long 3rd order tributary to the Youghiogheny River in Fayette County, Pennsylvania.
According to the Geographic Names Information System, it has also been known historically as:
Tub Run rises about 2.5 miles north-northeast of Flat Rock, Pennsylvania, and then flows southeast to join the Youghiogheny River in Youghiogheny River Lake about 0.25 miles north of Somerfield.
Tub Run drains of area, receives about 48.8 in/year of precipitation, has a wetness index of 365.42, and is about 87% forested.