Ahlmann is a surname. Notable people with the surname include:
Christian Ahlmann (born 1974), German equestrian Hans Wilhelmsson Ahlmann (1889–1974), Swedish geographer, glaciologist, and diplomat Lis Ahlmann (1894–1979), Danish weaver and textile designer Vilhelm Ahlmann (1852–1928), Danish-Swedish architect Viktor Ahlmann (born 1995), Danish football player
See also Else Ahlmann-Ohlsen (1907–1994), Danish fencer Ahlmann Glacier, a glacier of Antarctica Ahlmann Ridge, a ridge of Antarctica Erik Ahlman (1892–1952), Finnish philosopher and linguist