The Webster City Post Office is a historic building located in Webster City, Iowa, United States. Previous post office buildings in the city were housed in leased storefronts along Seneca Street. The Beaux-Arts style building was designed by the U.S. Treasury with James Knox Taylor as the supervising architect. Contractor Charles E. Atkinson completed the building in 1909. The stone building features a stone frieze, cornice, and a mansard roof. It was listed on the National Register of Historic Places in 1982.