Crosby is a town in Amite and Wilkinson Counties in the U.S. state of Mississippi. The population was 360 at the 2000 census. It is part of the McComb, Mississippi Micropolitan Statistical Area.
The town of Crosby has been known by several names throughout its history. It was first called Dayton in 1800, in honor of its first merchant, David Day. In 1917, the Foster Creek Lumber Company built a large mill here, and the town was renamed Stephenson, in honor of the owner of the lumber company, Fred Stephenson. When L.O. Crosby bought the lumber mill in 1934 the town changed its name to Crosby.
Crosby is located at 31°16′44″N 91°3′41″W / 31.27889°N 91.06139°W / 31.27889; -91.06139 (31.278816, -91.061488). The town straddles the boundary between Amite County on the north and east and Wilkinson County on the west. In the 2000 census, 258 of the town's 360 residents (71.7%) lived in Wilkinson County and 102 (28.3%) in Amite County.