Diplotomodon (meaning "double cutting tooth") is a dubious genus of theropod dinosaur, from New Jersey.

Diplotomodon is only known from a single tooth, holotype ANSP 9680, found near Mullica Hill in either the Navesink or Hornerstown Formation, marine deposits dating to the Maastrichtian stage of the late Cretaceous period.

Joseph Leidy originally described the tooth using the name Tomodon in 1865, considering it a carnivorous marine reptile, probably a plesiosaur.

[1] The generic name was derived from Greek τομός (tomos), "cutting", "sharp", and ὀδών (odon), "tooth".

However, this name had already been used for the snake genus Tomodon Duméril 1853 and Leidy changed it in 1868 to Diplotomodon, adding a Greek διπλόος (diploos), "double", at that time suggesting it was a fish.