Yahya Efendi or Molla Shaykhzadeh (born 1494, Trabzon - d. 1570, Istanbul), Ottoman Islamic scholar, sufi, and poet buried in Beshiktash, Istanbul.
He was a well known scholar, having served as a teacher of religious sciences during the reign of Sultan Suleyman the Magnificent. Yahya Efendi had close ties with the palace, and was consulted by the Sultan throughout his life. After retirement, he built a dergah, numerous buildings and charitable trusts in Beshiktash, and planted trees in the area.
Along with Aziz Mahmud Hudayi, Telli Baba, and Prophet Joshua, the four are considered to be the Four Patron Saints of the Bosphorus.