Araeosteus is an extinct genus of marine ray-finned fish, closely related to the modern-day prowfish. It contains a single species, A. rothi which is known from Late Miocene (Tortonian)-aged marine strata in Southern California, primarily the Diatom Beds of Lompoc (Monterey Formation) and the Santa Monica Mountains (Modelo Formation).

The generic name is a compound word meaning "slender bone." The specific name honors one Almon Edward Roth of Stanford University.