Monongahela or Mon Valley may refer to:
Places Monongahela, Pennsylvania, a city in Washington County Monongahela Cemetery, a historic cemetery in Monongahela City, Pennsylvania Monongahela City Bridge, spans the Monongahela River Monongahela Township, a rural township in Greene County, Pennsylvania Monongahela National Forest, a national forest in eastern West Virginia Monongahela River, a tributary of the Ohio River Battle of the Monongahela (9 July 1755), at the beginning of the French and Indian War Lake Monongahela, former Proglacial lake in Pennsylvania, West Virginia, and Ohio Monongahela Formation, a geologic group
Railways Monongahela Railway, a coal-hauling short line railroad in Pennsylvania and West Virginia in the United States Monongahela Connecting Railroad, a small industrial railroad in Pittsburgh, Pennsylvania Monongahela Freight Incline, a funicular railway that scaled Mount Washington Monongahela Incline, a funicular located near the Smithfield Street Bridge in Pittsburgh, Pennsylvania
Other Monongahela (album), a 1988 album by The Oak Ridge Boys Monongahela (fish), a genus of prehistoric fish Monongahela virus, an Orthohantavirus Monongahela culture, a Native American group USS Monongahela, one of various ships of the United States Navy the Mon Valley, a variant name of the PATrain commuter rail service Monongahela, a whaleship lost in 1853.