Adulis or Aduli is an archeological site in the Northern Red Sea of Eritrea, situated about 30 miles south of Massawa in the Gulf of Zula. It was the port considered part of the Kingdom of Aksum, located on the coast of the Red Sea. However recent excavation uncovers artifacts that predates the Axumite civilization. These civilization is now known as Adulitarian. Adulis Bay is named after the site. It is thought that the modern town of Zula may be the Adulis of the Aksumite epoch, as Zula may reflect the local name for the Ancient Greek Adulis.

Control of Adulis allowed Axum to be the major power on the Red Sea. This port was the principal staging area for Kaleb's invasion of the Himyarite kingdom of Dhu Nuwas around 520. While the scholar Yuri Kobishchanov detailed a number of raids Aksumites made on the Arabian coast (the latest being in 702, when the port of Jeddah was occupied), and argued that Adulis was later captured by the Muslims, which brought to an end Axum's naval ability and contributed to the Aksumite Kingdom's isolation from the Byzantine Empire and other traditional allies, the last years of Adulis are a mystery. Muslim writers occasionally mention both Adulis and the nearby Dahlak Archipelago as places of exile. The evidence suggests that Axum maintained its access to the Red Sea, yet experienced a clear decline in its fortunes from the seventh century onwards. In any case, the sea power of Axum waned and security for the Red Sea fell on other shoulders.