Willis, KS -- U.S. city in Kansas Population (2000): 69 Housing Units (2000): 29 Land area (2000): 0.168593 sq. miles (0.436653 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.168593 sq. miles (0.436653 sq. km) FIPS code: 79400 Located within: Kansas (KS), FIPS 20 Location: 39.724165 N, 95.505479 W ZIP Codes (1990): Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Willis, KS Willis