William Foster (1842 – 1909) was an architect in Iowa.
Together with Henry F. Liebbe (1851-1927), he worked as Foster & Liebbe, which designed numerous courthouses and other public buildings.
A number of his works are listed on the U.S. National Register of Historic Places.
Works include (with attribution):
Blair House, E. Washington St. and S. 2nd Ave., Washington, Iowa (Foster,William), NRHP-listedHawkeye Insurance Company Building, 209 Fourth St., Des Moines, Iowa (Foster,William), NRHP-listedE. R. Hays House, 301 N. 2nd St., Knoxville, Iowa (Foster,William), NRHP-listedIowa Men's Reformatory Historic District, N. High St., Anamosa, Iowa (Foster,William), NRHP-listedNaylor House, 944 W. 9th St., Des Moines, Iowa (Foster,William), NRHP-listedPage County Courthouse, Main St., Clarinda, Iowa (Foster,William), NRHP-listedParker's Opera House, 23 N. Federal Ave., Mason City, Iowa (Foster, William), NRHP-listedYoungerman Block, 206-208 4th St., Des Moines, Iowa (Foster, William), NRHP-listedEnglish Office Building for Iowa State College, Ames, IowaLucas County Courthouse, Chariton, IowaCentral School, Lake City, Iowa (Foster & Liebee), NRHP-listedCathedral Church of Saint Paul, 815 High St., Des Moines, Iowa (Foster and Liebbe), NRHP-listedCentral Christian Church, Des Moines, Iowa (Foster & Liebbe)Herndon Hall, 2000 Grand Ave., Des Moines, Iowa (Foster & Liebbe), NRHP-listedHospital for the Insane, Clarinda, Iowa (Foster & Liebbe)Iowa County Courthouse, Court Ave., Marengo, Iowa (Foster & Liebbe), NRHP-listedWapello County Courthouse, Court St., Ottumwa, Iowa (Foster & Liebbe), NRHP-listedWashington County Courthouse, N. B Ave., Washington, Iowa (Foster & Liebbe), NRHP-listedOne or more buildings in the Grinnell Historic Commercial District, Grinnell, Iowa (Foster & Liebbe), NRHP-listedOne or more works in the Winterset Courthouse Square Commercial Historic District, Winterset, Iowa (William Foster), NRHP-listed