Asaphus expansus (/ˈæsæfʌs ɛkspænsʌs/) is the type species of the asaphid trilobite genus Asaphus.

It was previously classified as Entomostracites expansus before being split off into its own genus.

[2] Most specimens have been obtained in Northern Europe, with one known exeption being in North America.

[3] Asaphus expansus differs from related species in its genus by having a cranidium that is considered broad, as opposed to its more medium sized counterparts.

Examples of these other species are A. fallax and A.