August Pieper (born 1844, Hannover – 29 April 1891, Hamburg) was a German architect, active in Dresden, Cologne and Hamburg. His brother was the engineer Carl Pieper (1842–1901), who also lived and worked in Hamburg in the 1880s.
He studied at secondary school and the university in his birthplace, before studying at the Vienna University of Technology under Friedrich von Schmidt, through whose efforts Pieper moved to Dresden in 1867. There Pieper designed the Christuskirche in Freital-Deuben, then All Saints Church and several villas on the city's Goethestraße (now Gret-Palucca-Straße). In 1873 he moved to Cologne and in 1879 to Hamburg.