Aragorn is a fictional character from J. R. R. Tolkien's fantasy universe of Middle-earth. Born in the year 2931 of the Third Age, the son of Arathorn II (TA 2873 - 2933) and his wife Gilraen (TA 2907 - 3007), he is a direct descendant of Elendil and Isildur. After his father's death in battle with Orcs, he was fostered in Rivendell by Elrond, his identity kept secret. He became the 16th Chieftain of the Dúnedain of the North as Aragorn II (The earlier Aragorn was one of his ancestors).

Already in his eighties by the time of the events of The Lord of the Rings, Aragorn has spent much of his life on errantry, usually under assumed names to protect the secret of his identity. He is known in Bree as Strider, a slightly disreputable persona he adopted while secretly guarding the Shire with his fellow Rangers (or Dúnedain).

The restoration of the line of Elendil to the throne of Gondor is a major subplot of The Lord of the Rings; Aragorn's adventures not only aid Frodo in his Quest, but also bring him closer to the kingship. Upon Sauron's defeat, in TA 3019, Aragorn is crowned as King Elessar (Quenya for Elfstone). He marries Arwen Undómiel shortly afterwards, and rules the reunited kingdom of Gondor and Arnor until year 120 of the Fourth Age (TA 3141). He died after 210 years of life and 122 years of reign. He was succeeded by his son Eldarion. A number of daughters are also mentioned but not named.

In The Lord of the Rings movies (2001-2003), Aragorn is played by Viggo Mortensen.

Aragorn is also known as the Dunadan ("Man of the West"), Strider, Elessar Telcontar ("elfstone strider"), Longshanks and Estel ("hope").