Zoroastrianism in Iran

Zoroastrianism is considered to be the oldest religion still practiced in Iran. It is an Iranian religion that emerged around the 2nd millennium BCE, spread through the Iranian plateau, and eventually gained official status under the Achaemenid Empire in the 6th century BCE. It remained the Iranian state religion until the 7th century CE, when the Arab conquest of Persia resulted in the fall of the Sasanian Empire to the nascent Rashidun Caliphate. Over time, Zoroastrians became a religious minority amidst the Islamization of Iran, as due to persecution many fled east to take refuge in India. Some of Zoroastrianism's holiest sites are located in Iran, such as Yazd.

Today, Iran has the second largest Zoroastrian population in the world, behind only India and possibly the Kurdistan Region. The official Iranian census of 2011 recorded a total of 25,271 Zoroastrians in the country, but several unofficial accounts suggest higher figures.