Blainsburg is an unincorporated community in Washington County, Pennsylvania, United States.

Named after James G. Blaine, Blainsburg is part of the California Area School District.

The bedroom community is situated on the bluff above and slightly north-northwest of West Brownsville on the river bottom below.

[2] The parent and child communities are on the inside curve of a great meander in the Monongahela River in Southwestern Pennsylvania creating a degraded cut bank turned ramp and terrace on the opposite shore where Brownsville is situated.

Pennsylvania Route 88 climbs roughly parallel (starting from farther south in West Brownsville and rises at a slower rate, so the higher side of Blainsburg is atop a bluff lining and overlooking the moderated climb of the highway.)