Based on the widely held view, Zoroaster was a prophet of Allah whose religion came under distortion later on.
Although there are different opinions regarding the personality and the life of Zoroaster and too much ambiguity about his life, he was, based on the widely held view, a prophet of Allah whose religion came under distortion later on.
Zoroaster in the Qur'an
There is no mention of such an individual as 'Zoroaster' in the Quran, however, the name Magians [Majoos] is alluded to once in the Quran [along with Jews and Christians] which, according to some, is in reference to the followers of Zoroaster [i.e. Zoroastrians]:
Indeed, those who have believed and those who were Jews and the Sabeans and the Christians and the Magians and those who associated with Allah - Allah will judge between them on the Day of Resurrection. Indeed, Allah is, over all things, Witness.1
It can be understood from this verse that Zoroastrians followed a Divine religion, book2 and prophet, for they are mentioned as different from the polytheists and in the row of those having Heavenly religions.
Some Hadiths about Zoroastrians
We read in some Islamic narrations that the polytheists of Mecca asked the Prophet (S) to take capitation from them and let them worship idols. The holy Prophet (S) answered them he would not take capitation from anyone except the people of the Book. The polytheists wrote in answer to him (S),
“How do you speak like that while you have taken capitation from the Magians inhabiting the region of Hijr?”
The Prophet (S) said:
“Verily Magians had a prophet, who was killed, and a Book which was burnt.”3
Imam Sajjad, Ali-ibn-il-Husayn (as) in a tradition narrated that the holy Prophet (S) said:
"Treat them [Magians] in the same manner that you treat the People of the Book."4
Footnotes:
1. The Holy Qur'an, [22:17]
2. It is known that Zoroaster had a book by the name of Avesta which was destroyed in Alexander's invasion of Iran, and later it was rewritten at the time of one of the Kings of Sasanian Dynasty.
3. Al-Kafi, vol. 7, p. 207
4. Wasa’il-ush-Shi‘ah, vol. 11, chapter 49, p. 96