Greens Run is a long 2nd order tributary to Buffalo Creek in Brooke County, West Virginia.
Greens Run rises about 0.5 miles north-northwest of Pettit Heights, West Virginia, and then flows northeast to join Buffalo Creek about 0.25 miles south of Marshall Terrace.
Greens Run drains of area, receives about 39.9 in/year of precipitation, has a wetness index of 280.76, and is about 85% forested.