M1900 may refer to:
FN M1900 or Browning M1900, pistol Colt M1900, pistol 76 mm gun M1900 Mannlicher M1900, a rifle, see Ferdinand Mannlicher M1900 variant of the Hotchkiss M1914 machine gun 5-inch gun M1900, a US Army artillery piece 6-inch gun M1900, a US Army artillery piece
See also M0 (disambiguation)