The Pepsinae are a subfamily of the spider wasp family, Pompilidae, including the two genera of large tarantula hawks, as well as many genera of smaller species.

A female spider wasp generally captures and stings a spider to paralise it; this is for their larvae to feed on. However, the wasps of this subfamily display a range of nesting behaviours:

Pepsinae can be defined by:

The subfamily Pepsinae comprises 84 genera. These include 16 genera of Ageniellini, 7 genera of Deuterageniini, 48 genera of Pepsini, 11 genera of Priocnemini, 1 genus of Psoropempulini, and 1 genus unplaced to tribe.