In the fictional universe of J. R. R. Tolkien, Ar-Pharazôn (Quenya: Tar-Calion) was the 25th and last king of Númenor.

Ar-Pharazôn was the nephew of King Tar-Palantir and husband of Tar-Palantir's daughter, Míriel. Míriel was the rightful heir to the throne of Númenor, but Ar-Pharazôn usurped her throne.

He attacked Mordor and brought Sauron back as a hostage to his kingdom, but Sauron was able to corrupt Ar-Pharazôn and convinced him to attack Valinor. In retribution, the Valar sank Númenor beneath the ocean.

Preceded by:
Tar-Palantir
List of rulers of Númenor

Ar-Pharazôn was married to his cousin, Míriel, who was the daughter of King Tar-Palantir, whom Ar-Pharazôn succeeded when he took the throne from his wife. His father was Gimilkhâd, Tar-Palantir's younger brother.