Diana is a goddess in Roman and Hellenistic religion, primarily considered a patroness of the countryside, hunters, crossroads, and the Moon. She is equated with the Greek goddess Artemis, and absorbed much of Artemis' mythology early in Roman history, including a birth on the island of Delos to parents Jupiter and Latona, and a twin brother, Apollo, though she had an independent origin in Italy.

Diana is considered a virgin goddess and protector of childbirth. Historically, Diana made up a triad with two other Roman deities: Egeria the water nymph, her servant and assistant midwife; and Virbius, the woodland god.

Unlike the Greek gods, Roman gods were originally considered to be numina: divine powers of presence and will that did not necessarily have physical form. At the time Rome was founded, Diana and the other major Roman gods probably did not have much mythology per se, or any depictions in human form. The idea of gods as having anthropomorphic qualities and human-like personalities and actions developed later, under the influence of Greek and Etruscan religion.

By the 3rd century BCE, Diana is found listed among the twelve major gods of the Roman pantheon by the poet Ennius. Though the Capitoline Triad were the primary state gods of Rome, early Roman myth did not assign a strict hierarchy to the gods the way Greek mythology did, though the Greek hierarchy would eventually be adopted by Roman religion as well.

Once Greek influence had caused Diana to be considered identical to the Greek goddess Artemis, Diana acquired Artemis's physical description, attributes, and variants of her myths as well. Like Artemis, Diana is usually depicted in art wearing a short skirt, with a hunting bow and quiver, and often accompanied by hunting dogs. A 1st-century BCE Roman coin (see above) depicted her with a unique, short hairstyle, and in triple form, with one form holding a bow and another holding a poppy.