In the fiction of J. R. R. Tolkien, Andúnië was an important city and port in the realm of Númenor, located on the Bay of Andúnië in the Andustar region, Andúnie was initially the chief city of Númenor, as it was the haven where the Eldar of Tol Eressëa would most often visit the Elf-friends.

Andúnië was home to the Lords of Andúnië descented by Valandil, the highest nobles of Númenor, who were leaders of the Elf-friends (also known as The Faithful) who advocated continued friendship with the Elves and obedience to the Valar.

However, as the Shadow was falling above Númenor, Armenelos became larger and more important than Andúnie. By the close of the Second Age, many of the Faithful from Andúnië were labelled as dissidents by the King's Men and deported to the haven of Rómenna and other eastern regions.

Amandil, the last of them, was the ancestor of the Kings of the Dúnedain in Middle-earth.