The Woodbury County Courthouse is a building that fills an entire quarter block in Sioux City, Iowa. It is regarded as "one of the finest Prairie School buildings in the United States" and has been declared a National Historic Landmark. It is used for legal proceedings in the county.
Though Sioux City was made the county seat in 1858, the first permanent Woodbury County courthouse was not finished until 1878.In 1914, the county determined that the courthouse was too small for the city and they decided to build a new one. The old courthouse was sold and the new one, designed by the Minneapolis architect George Grant Elmslie in collaboration with the Sioux City architect William L. Steele and Elmslie's partner, William Gray Purcell, was constructed from July 10, 1916 to March 1, 1918 at a cost of $850,000.