Palinurus (Palinūrus), in Roman mythology and especially Virgil's Aeneid, is the coxswain of Aeneas' ship. Later authors used him as a general type of navigator or guide. Palinurus is an example of human sacrifice; his life is the price for the Trojans landing in Italy.

In Book 3, which tells of the Trojans' wanderings after The Fall of Troy, he is singled out as an experienced navigator. In Book 5, when the Trojans have left Carthage, he advises Aeneas to forestall sailing to Italy and to wait out a terrible storm on Sicily, where they hold the funeral games honoring Aeneas's father, Anchises. After they leave Sicily for Italy, Palinurus, at the helm of Aeneas's ship and leading the fleet, is singled out by Virgil in second person when it becomes clear that he is the one whom the gods will sacrifice to guarantee safe passage to Italy for the Trojans: unum pro multis dabitur caput, "one single life shall be offered to save many." Drugged by the god of sleep, he falls overboard; Aeneas takes over the helm and, unaware of the gods' influence, accuses Palinurus of complacency: "You, Palinurus, placed too much trust in the sky and the ocean's / Calm. You'll lie naked and dead on the sands of an unknown seashore."

Aeneas next encounters Palinurus in the underworld, before he crosses Cocytus (which the ghosts of the unburied dead cannot cross into the underworld proper), where he asks how it came to be that he died despite a prophecy from Apollo that he would reach Italy unscathed. Palinurus responds that he survived the plunge into the sea, was washed ashore after four days near Velia, and was killed there and left unburied. The Cumaean Sibyl, who has guided Aeneas into the underworld, predicts that locals will come and build him a mound and the place will be named Cape Palinuro in his honor.

The death of Palinurus is, according to classical scholar Bill Gladhill, "the most lucid example of this representation of human sacrifice in which the divine perspective construes his death in terms of unus pro multis".

Scholars have recognized in Palinurus a counterpart of Homer's Elpenor, who dies while Odysseus is on Circe's island; in their haste, his comrades do not look for him and his body remains unburied. When Odysseus is in Hades, he is accosted by Elpenor, and after his return he cremates Elpenor's body and erects a monument for him. Virgil takes that tradition, and changes details, such as the cremation ceremony, to fit Roman custom. Palinurus falling overboard shows the influence of the "shipwreck" trope, popular in the centuries before Virgil; Richard F. Thomas read the Palinurus episode in the light of the epigrams found in the Milan Papyrus, ascribed to Posidippus.

One of Martial's epigrams (3.78) plays on Palinurus's name by turning it into an obscene pun:

Minxisti currente semel, Pauline, carina.
Meiere vis iterum? Iam Palinurus eris.

("You pissed one time, Paulinus, as the ship hurried along. / Do you want to piss again? Then you'll be Palinurus.")
"Palinurus" is assigned a humorous etymology, as though it were derived from πάλιν ("again") and the root of οὐρέω ("to urinate"), thus πάλιν-οὖρος ("again-pisser").