Reimann is a German surname. Notable people with the surname include:
Aribert Reimann (born 1936), composer and pianist
Bernhard Riemann (1826–1866), mathematician
Gotthold Reimann, full name Immanuel Gotthold Reimann (1859–1932), South Australian teacher of music
Günter Reimann (1904–2005), economist
Hans Reimann (writer) (1889–1969), German writer
Hans-Georg Reimann (born 1941), East German racewalker
Heinrich Reimann (1850–1906), musicologist
Katya Reimann (born 1965), novelist
Lukas Reimann (Swiss politician) (born 1982)
Robert Reimann (Swiss politician) (1911–1987)
Robert Reimann (US Navy officer)