Ahura Mazda, the supreme creator god in Zoroastrianism the religion of Persia before the establishment of Islam in the 7th century. The term Ahura originally referred to 33 ruling gods in ancient, pre-Zoroastrian religions in Persia and India. Zoroaster the prophet who founded Zoroastrianism, preached against all the other gods except Ahura Mazda, who, he said, should be worshipped eternally. Ahura Mazda means "Lord Wisdom" in the ancient Avestan language of Persia. In the writings that express Zoroaster's teachings, Ahura Mazda is characterized as a benevolent, wise creator and is pitted against Angra Mainya, a demon whose purpose is to destroy the earth and its inhabitants.

Ahura Mazda has no physical form, but Zoroastrians worship him through his attributes, or Amesha-Spentas (Holy Immortals). The Amesha-Spentas reflect the different aspects of the divine nature of Ahura Mazda. These aspects are Creative Spirit, Righteousness, Good Purpose, Devotion, Power, Health, and Long Life. Some are considered male, others female. Scholars sometimes compare the Amesha-Spentas with the archangels of Christianity.

Ahura Mazda is symbolized by fire, which is considered the most holy substance by Zoroastrians because it represents divine emanation (outpouring). Because fire symbolizes Ahura Mazda's power, presence, and purity, it must never be extinguished in fire temples. These sacred fires are maintained by a hereditary male priesthood who learn required prayers and perform ritual duties.

Ahura Mazda was first officially worshipped as an all-powerful god by Darius I. Worship of Ahura Mazda continues today primarily in India in the vicinity of Mumbai (formerly Bombay) among Parsis, Zoroastrians who migrated from Iran to India in the 10th century. Zoroastrian communities also survive in Iran. To express their faith, members of the community are advised to wear special clothing, observe seven annual festivals, and pray five times a day. At the end of time, the Zoroastrian community foresees the resurrection of all believers into a kingdom on earth ruled over by Ahura Mazda.