This study was conducted to determine the taxonomic, ecological and distributional characteristics of sponge species distributed along the Aegean Sea coast of Türkiye. Samples were collected from 36 coastal and 7 offshore stations of different depths (35–400 m) and biotopes. Benthic sampling was performed by diving at coastal stations and by bottomtrawling at offshore stations. As a result of the faunistic analysis of the samples, a total of 114 species belonging to 3 classes, 17 orders and 44 families were identified, of which 9 species were new to the eastern Mediterranean, 10 species were new to the Aegean Sea, and 13 species were new to the coasts of Türkiye. Among the biotopes, rocky shores were characterized by the highest number of sponge species (85 species), while the stony coral Cladocora caespitosa was represented by the lowest number of species (3 species). The majority of sponge species (73 species) were found in the depth interval 10–20 m. Among the sponges identified, only one invasive alien species, namely Paraleucilla magna, was found on artificial substrata at one station in the inner part of Izmir Bay. The majority of the species (71% of the total number of species) found in the study area have the Atlanto-Mediterranean distribution pattern.