A priest in the time of David (2 Sam. 20: 25). He supported David during the revolt of his son Absalom and urged him to appoint Solomon as his successor (1 Kgs. 1: 8; 1: 39–45). According to 1 Chron. (6: 1–8; 49–53) he was descended from Aaron, so was an Aaronite priest, but it has been widely held by modern scholars that he was of Jebusite origin, that is, one of the inhabitants of the city conquered by David. His name shows similarity with that of Mel-chizedek, described in Gen. 14 as priest of Jerusalem.

The descendants of Zadok controlled the Jerusalem priesthood (Ezek. 40: 46) until 171 BCE when the office passed to the Hasmoneans. The Zadokite priests were the first leaders of the community established at Qumran. The name Sadducees may be connected with Zadok.