Which constellation is named after a winged horse?

The constellation named after a winged horse is Pegasus.

Pegasus is a northern-sky constellation named for the winged horse of Greek mythology. It was among the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 constellations officially recognized today.

In the best-known myth, Pegasus sprang from the blood of Medusa after the hero Perseus beheaded her. The horse later became the companion of Bellerophon, who rode it while fighting the fire-breathing Chimera. Pegasus was also associated with the spring Hippocrene, which legend said was created by one of its hoof strikes and inspired poets.

A prominent guide to Pegasus is the Great Square, a large pattern formed by four stars, although one of those stars, Alpheratz, is officially part of Andromeda. Pegasus is sometimes confused with Equuleus, a much smaller neighboring constellation representing a little horse, or with Centaurus, which depicts a different mythological creature.