Henry C. Koch (March 20, 1841 – May 19, 1910) was a German-American architect based in Milwaukee, Wisconsin.
Born in Hanover in the Kingdom of Hanover, Koch immigrated as a toddler with his family to the United States. His architectural career began at the age of 16 when he worked for early Milwaukee architect, G. W. Mygatt. He enlisted in the Civil War with the 24th Wisconsin Infantry as a private, later becoming a draftsman on General Philip Sheridan's staff. After the war Koch returned to Milwaukee, where he formed a partnership with Mygatt until 1870, when he started his own firm.
One of Koch's most significant works was the 1895 Milwaukee City Hall. Koch designed buildings for the University of Wisconsin. He designed 26 courthouses and more than 120 schools.
He married and had two sons, Harry and Armand D. Koch. The latter also became an architect, joining his father's firm in the 1890s and helping with the design of the Milwaukee City Hall.Calvary Presbyterian Church, Milwaukee, Wisconsin, 1870
Turner Hall, Milwaukee, 1882
Stutsman County Courthouse and Sheriff's Residence/Jail, Jamestown, North Dakota, 1883
David W. and Jane Curtis House, Fort Atkinson, Wisconsin, 1885
Mahaska County Courthouse, Oskaloosa, Iowa, 1886
Science Hall, on the campus of the University of Wisconsin, 1888
Golda Meir School, Milwaukee, 1890
The Pfister Hotel, Milwaukee, 1890–93
Montgomery County Courthouse, Red Oak, Iowa, 1891
Jefferson County Courthouse, Fairfield, Iowa, 1893
Gesu Church, Milwaukee, 1894
Milwaukee City Hall, Milwaukee, 1895
Webster County Courthouse, Fort Dodge, Iowa, 1902
The Roosevelt New Orleans Hotel, New Orleans, Louisiana, 1908