Kossmann or Koßmann is a German surname. Notable people with the surname include:
Alfred Kossmann, (1922-1998), a Dutch poet and prose writer.
Ernst Kossmann, (1922-2003), a Dutch historian and twin brother of Alfred
Karl-Richard Koßmann, (1896-1947), a Generalmajor in the Wehrmacht during World War II
Kurt Kossmann, (born 1971), an American professional race car driver
Yvette Kosmann, (born 1941), a French mathematician and professor