Coastal environments, such as bays, are essential to the development of fishery resources due to their economic and ecological importance. This paper presents an updated checklist of coastal marine fishes as part of a long-term monitoring program in Aratu Bay (2014–2024), Bahia state, eastern Brazil. A total of 109 species belonging to 58 families and 24 orders were cataloged. Five endemic species and ten species listed as at risk according to the IUCN criteria (from Vulnerable onwards) were identified. The Carangidae was the most representative family in terms of species number, followed by Gobiidae and Sciaenidae. The ichthyofauna was dominated by mobile invertebrate feeders and macrocarnivores. Two non-native species were observed in the region: the Muzzled blenny, Omobranchus sewalli and the mud sleeper Butis koilomatodon. Aratu Bay supports a diverse ichthyofauna with diverse trophic guilds and habitats, rendering it an important area for the feeding and development of economically valuable species, including those facing threats.