Köhnen, or Kohnen, is a surname. Notable people with the surname include:
Egon Köhnen (born 1947), German footballer Friederun Köhnen (1942–2026), German television chef and food industry executive Heinz Kohnen (1938–1997), German scientist and geophysicist Joseph Kohnen (1940–2015), Luxembourgish writer Julia Kohnen Griffey (born 1992), American marathon runner Natascha Kohnen (born 1967), German politician Ralph B. Kohnen (1935–2008), American politician
See also Kohnen Station, German summer-only polar research station in the Antarctic