Tar-Alcarin (2406 - 2737 S.A., r. 2657 - 2737 S.A.) was the 17th ruler of Númenor. His parents were the ruling Queen, Tar-Vanimeldë, and her consort, Herucalmo. Tar-Alcarin should have succeeded his mother upon her death, but Herucalmo usurped the throne and held it for twenty years before he died, and Tar-Alcarin rightfully gained the throne. His name means "Glorious".
The period in which he ruled was still a mostly peaceful one in Númenor, but in Middle-earth Sauron ruled the lands, and the shadow had fallen on Númenor as well. Herucalmo's usurping of the throne was generally considered an evil deed by the people.
Tar-Alcarin ruled for eighty years, then was succeeded by his son, Tar-Calmacil.