| Named By: | P. M. Galton & H. inD. Sues in 1983 |
| Time Period: | Late Maastrichtian, 66 Ma |
| Location: | USA - Ferris Formation, Hell Creek Formation |
| Size: | Skull reconstructed to be 46 centimetres long. Total body size uncertain but may roughly have been just over three meters long |
| Diet: | Herbivore |
| Fossil(s): | Remains of several individuals |
| Classification: | | Chordata | Reptilia | Dinosauria | Ornithischia | Pachycephalosauridae | Pachycephalosaurinae | |
Stygimoloch is a controversial genus of pachycephalosaurid dinosaur from the end of the Cretaceous period, roughly 66 million years ago. It is currently known from the Hell Creek Formation, Ferris Formation, and Lance Formation of the Western Interior (United States), where it lived alongside Tyrannosaurus and Triceratops.