Which Zoroastrian deity is associated with fire?

The Zoroastrian deity associated with fire is Atar.

Atar, also written Ātar, Adar, or Atash in related Iranian forms, is the Zoroastrian sacred fire and the divine power associated with heat and light. In later Zoroastrian theology, Atar is personified as a yazata, or worthy of worship, and is described as the son of Ahura Mazda. Fire is revered as a visible sign of purity, truth, and divine presence.

Atar's role developed over time. In the Gathas, the oldest Zoroastrian hymns, fire is often presented more abstractly as a medium of judgment, illumination, and revelation. In later Avestan texts, Atar becomes more explicitly the divine presence represented by blazing fire itself.

Zoroastrians do not worship fire as a simple physical object. Carefully tended temple fires serve as focal points for prayer and ritual purity, alongside clean water. Atar is also linked with Asha Vahishta, the principle of truth and righteousness. Anahita is associated primarily with waters and fertility, Mithra with covenants and light, and Rashnu with judgment.