Jacob Querido (‘the Beloved’, c.1650-1690 in Alexandria, Egypt) was the successor of the self-proclaimed Jewish Messiah Shabbatai Zevi. Born in Salonika, he was the son of Joseph the Philosopher and brother of Jochebed, Shabbatai Zevi last wife. Jochebed (also called ‘Ā’ishah following her conversion to Islam) claimed that he was the reincarnation of her late spouse, so that he might succeed to the leadership of Sabbatai's followers. He attracted a considerable following of his own, called Ya‘aqōviyīm or Yakubiler.
Querido converted to Islam taking his name as Yakup in 1687 playing an important role in the Donmeh. He led his disciples on a pilgrimage to Mecca. He died in Alexandria on his way back, and was succeeded by his son Berachiah Russo (Osman Baba) (c.1630-1706).