Aksu is a neighborhood in Hendek District, in Sakarya Province, Türkiye. Aksu lies at 607 m above sea level, in the Elmacık Dağı mountains. It has 728 inhabitants. The nearest city is Hendek, 13.8 km to the northwest. Among the landmarks around are Sangarius Bridge (41 km) and Prusias ad Hypium (29 km).