Simpson -- U.S. County in Mississippi Population (2000): 27639 Housing Units (2000): 11307 Land area (2000): 588.731147 sq. miles (1524.806607 sq. km) Water area (2000): 1.796433 sq. miles (4.652740 sq. km) Total area (2000): 590.527580 sq. miles (1529.459347 sq. km) Located within: Mississippi (MS), FIPS 28 Location: 31.911087 N, 89.861628 W Headwords: Simpson Simpson, MS Simpson County Simpson County, MS