Hack Kampmann (1856 in Ebeltoft, Denmark – 1920) was a Danish architect. His parents were the priest Christian Peter Georg Kampmann and Johanne Marie Schmidt. He entered the Royal Academy of Arts School of Architecture and graduated in 1882, receiving the prestigious small gold medal.
Kampmann went on numerous study trips in Europe on several scholarships, and visited northern Italy, Greece and Sweden. He also attended the Beaux-Arts Academy in Paris and worked with professor Jacques Hermant.
On his return to Denmark he drew a series of private and public buildings in Denmark. Among his major works are the Provincial Archives (1890–91) in Viborg, Jutland; the Aarhus Theater (1898–1900); Marselisborg Palace, built 1899–1902 as a wedding gift from the people to Crown Prince Christian (later Christian X); and the extension of the Ny Carlsberg Glyptotek in Copenhagen.
Kampmann was the leading Danish proponent of the Danish national romantic style and, through his Police Headquarters in Copenhagen (1918–22), an initiator of 1920s Neoclassicism. This last building was completed after his death in summer 1920 by his two sons and Aage Rafn. He is one of the most influential architects in Danish architectural history and also neoclassical architecture.