Megalolamna is an extinct genus of lamniform shark that belongs to the family Otodontidae. Its name comes from the similarity of its teeth to those of the extant shark genus Lamna. It is known from the early Miocene of Peru, Japan, and California and North Carolina in the United States, implying a cosmopolitan distribution. It is considered to be the sister genus of Otodus. The study of Megalolamna's taxonomic relationships also demonstrates the possibility that Otodus needs to include the species sometimes assigned to Carcharocles (i.e., the megatoothed lineage, including megalodon) in order to be monophyletic.