The C. Bascom Slemp Federal Building, also known as the Big Stone Gap Post Office and U.S. Post Office and Courthouse, is a historic courthouse and post office building located in Big Stone Gap, Wise County, Virginia.

It was designed by the Office of the Supervising Architect under James Knox Taylor and built between 1911 and 1913.

It is a three-story, seven-bay, stone building with a low hipped roof in the Second Renaissance Revival style.

The front facade features a three-bay Tuscan order portico consisting of four pairs of coupled, unfluted columns.

This article about a property in Wise County, Virginia on the National Register of Historic Places is a stub.