A halo (also known as a nimbus, aureole, glory, or gloriole) is a ring of light that surrounds a person in art. They have been used in the iconography of many religions to indicate holy or sacred figures, and have at various periods also been used in images of rulers or heroes. In, among other religions, Hellenistic Greek, Roman, Buddhist and Christian sacred art, sacred persons may be depicted with a halo in the form of a golden, yellow or white circular glow around the head, or around the whole body, this last often called a mandorla.

In popular piety, this practice has led to the literal belief that saints have visible haloes around their heads, rather than it be understood as a metaphorical representation. Some faithful believe the halo to be equivalent to the aura of some Eastern religions, and as with the latter, believe that haloes are visible to those with perception. Of the many stories about saints, some reports claimed that a saint was literally glowing.

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