Palaeolagus, an early lagomorph from the Eocene–Oligocene of North America, is important for our understanding of the anatomy of the hypothetical last common ancestor of extant lagomorphs – the leporids (hares and rabbits) and ochotonids (pikas). Even though Palaeolagus was first described nearly 150 years ago and is represented by numerous well-preserved skeletons, several details of its cranial anatomy have remained unknown due to the limitations of physical preparation of its small, delicate fossils. Using micro-computed tomography and 3D imaging, numerous, previously unknown details of the cranial anatomy of Palaeolagus are reconstructed, including details of palatal and basicranial morphology. The new anatomical data allow for a better understanding of the evolution of the early lagomorph body plan and will form the basis of future studies of the phylogenetic interrelationships within Lagomorhpa in particular and Glires in general.