魔法禁書目錄
Maiko Iuchi of I've Sound is in charge of music for the series' three seasons. The first opening theme music, used in episodes 1–16 of the first season of "A Certain Magical Index", is "PSI-Missing", while the second one, used in episode 17 onwards, is "Masterpiece", both performed by Mami Kawada. The first ending theme music, used in episodes 1–19, is , while the second one, used in episode 20 onwards, is , both performed by Iku. The opening theme music for "A Certain Magical Index" PSP game is "Answer" by Maon Kurosaki.