According to the United States Census Bureau, the city has a total area of 12.90 sqmi, of which 12.80 sqmi is land and 0.10 sqmi is water. Pittsburg sits in the Ozark Highlands region, a mix of prairie and forests.

It lies 90 mi west of Springfield, Missouri, 124 mi south of Kansas City, Missouri, and 137 mi northeast of Tulsa, Oklahoma.