Gravitholus (meaning 'heavy dome') was a genus of pachycephalosaurid dinosaur from the late Cretaceous period (Campanian stage, around 75 million years ago).

It was a pachycephalosaur, and like other pachycephalosaurids the skull roof formed a thick dome made of dense bone, which may have been used in head-butting contests over mates or territory.

[citation needed] Gravitholus was initially described as one of several pachycephalosaurids known from Dinosaur Park, including Stegoceras validum, Hanssuesia sternbergi and Foraminacephale brevis.

A 2023 publication by Dyer et al. found Gravitholus and Hanssuesia to be synonymous with Stegoceras, thus decreasing the diversity of Dinosaur Park pachcephalosaurids to only two valid taxa.

This conclusion was reached because new morphological data recovered from synchrotron scanning of the skull revealed Gravitholus to be virtually identical to mature Stegoceras.