Oswego isat (37.167728, -95.109453). The city is about north of the Oklahoma state line and west of the Missouri line. It is along the southern bluffs, overlooking the Neosho River valley. It is at the junction of U.S. Route 59 and U.S. Route 160. The United States Census Bureau says that the city has a total area of . Of that, is land and is water.