West Pittsburg is an unincorporated community and census-designated place in southern Taylor Township, Lawrence County, Pennsylvania, United States. As of the 2010 census it had a population of 808. It is located in the Beaver River valley 5 miles south of New Castle. Its main street is the north-south Pennsylvania Route 168, which crosses the river at the southern end of the community. The community is 46 miles north-northwest of the city of Pittsburgh.