Wilhelm Altmann (4 April 1862 – 25 March 1951) was a German historian and musicologist.
Altmann was born in Adelnau (Odolanów), Province of Posen, and died in Hildesheim. Wilhelm Altmann and his wife Marie née Louis are buried in Hildesheim, Peiner Straße on the cemetery Nordfriedhof (Zentralfriedhof). The couple had three children: Ulrich (1889-1950), Ursula and Berthold (1896-1992).