This article is about the Christian symbol. See Halo (disambiguation) for other uses of the term.

In Christian sacred art (Eastern and Western churches), holy persons (saints) are depicted with a halo, a golden, yellow or white circular glow, around the head. It is sometimes called a nimbus as well. See iconography.

The halo appears in the art of ancient Greece and Rome, and was incorporated into Christian art sometime in the 4th century. Round halos are used to signify saints. A cross within a halo is used to represent Christ. Triangular halos are used for representations of the Trinity. Square halo are used to depict unusually saintly living personages.

In popular piety, this practice has led to the belief that saints during their earthly life actually walked around with a halo around their head. Of the many wonderful stories about saints, some report that a saint was literally glowing. This is called the aureole, a lemon-drop-shaped item that appears to radiate from the entire body of the holy being. Finally, there is also "glory," a glowing effusion used to cover up depictions of genitalia.

The halo underwent an interesting transformation during the Renaissance. Originally, the halo represented a glow of sanctity emanating from the head. Since it was conventionally drawn as a circle, during the Renaissance, when perspective became more important in art, the halo was changed from an aura surrounding the head to a golden ring that appeared in perspective, mysteriously floating above the heads of the saints.