In Greek mythology, sileni were a race of half-horse, half-humans, unlike the satyrs, who were half-goat.

The Sileni were followers of Dionysus. They were drunks, bald and fat with thick lips and squat noses, and the ears and tail of a horse. Later, sileni lost the plural connotation and the only references were to one named Silenus (Roman equivalent: Silvanus), the teacher and faithful companion of the wine-god Dionysus. A notorious consumer of wine, he was usually drunk and had to be supported by satyrs or carried by a donkey. When the Phrygian king Midas took the drunk Silenus in his house, Dionysus handsomely rewarded Midas for his hospitality. Silenus was thought to have much wisdom and be able to reveal important secrets to mortals if captured and questioned.

Silenus was equated with the Roman Silvanus whose name simply means "of the woodland" and Etruscan Selvans.