Pharnajom or Pharnajob (Georgian: ფარნაჯომი, ფარნაჯობი; died 90 BC) was a king (mepe) of Iberia from 109 to 90 BC, the fourth in the P'arnavaziani line. He is known exclusively from the royal list included in the medieval Georgian chronicles.

Pharnajom succeeded on death of his father, Mirian I in 109 BC. He is reported to have added another idol, that of the god Zaden, to the Iberian pagan pantheon, and to have built a fortress to house it.

Prior to 90 BC, Pharnajom converted to Zoroastrianism, abandoning K'art'velian polytheism.^[1] His nobles sent an ambassador to the king of Armenia promising the throne to his son, Artaxias.^[2] At the battle of Tasiri between Pharnajom and his nobles, the king is defeated and killed, and the crown given to Artaxias I of Iberia.^[3] Pharnajom's son, Mirian (Mirvan), survives, however, to be taken and brought up at the Parthian court.