Abstract Cretaceous ichthyosaurs were relatively diverse in temperate latitudes, but few species have been described from the palaeotropics. Here, we describe a new ophthalmosaurid ichthyosaur, M uiscasaurus catheti gen. et sp. nov., from the B arremian– A ptian aged P aja F ormation of C olombia. This species is known only from a partial skull and differs from all other ichthyosaurs in the unusual configuration of the external narial opening, slender rostrum, narrow postorbital region, and gracile dentition. It is the second ichthyosaur described from the P aja F ormation, suggesting moderate taxonomic and ecological ichthyosaur diversity in the region during the E arly C retaceous.