We investigated ant species richness and abundance of the maritime forest and dune habitats of Assateague Island, a barrier island off the coasts of Maryland and Virginia. We paired 5 transects of 100 m in forest habitats with 5 transects in dune and grassland habitats, with pitfall traps set every 10 m along each transect. During a 5-month period (May–September), we collected 26 species of ants, including 9 that had not been previously recorded on the island and 2 that had never been recorded east of Maryland's Chesapeake Bay. Forest habitats had a significantly higher species richness than the dunes, with 24 and 14 species collected, respectively. Our research provides baseline data on ant species richness for this temperate barrier island using pitfall-collection methods. We provide evidence for forest habitats supporting higher species richness and make suggestions for future research.