A dastūr,^{[pronunciation?]} sometimes spelt dustoor, is a term for a Zoroastrian high priest who has authority in religious matters and ranks higher than a mobad or herbad. In this specific sense, the term is used mostly among the Parsis of India. The term has also been used in a secular sense to refer to a prime minister, minister or government councillor.^[1]

The first person to be accorded the title Dastur was Meherji Rana (born 1514 at Navsari). He was invited by Akbar to his court in 1578 AD.^[2] He was accorded the title in 1579 AD by the local Zoroastrian priests thus establishing a seat (Gaadi, similar to the seat of a Bhattaraka or Sankaracharya). Dastur Kaikhushru Cowasji Ravji became the eighteenth successor to the seat and title of MeherjiRana in 2019.^[3] He became a Mobed 59 years earlier.