Jwaji of Geumgwan Gaya (died 421) (r. 407–421) was the sixth ruler of Geumgwan Gaya, a Gaya state of ancient Korea. He was the son of King Ipum and Queen Jeongsin. He married Queen Boksu, who was the daughter of the high official (daeagan) Donyeong. She gave birth to the crown prince Chwihui.
The Samguk Yusa reports that he appointed the relatives of a favoured concubine to high office, and that this led to political trouble. Furthermore, Silla took advantage of the kingdom's vulnerability and invaded. After the courtier Pak Won-to remonstrated with him, the king went to a fortuneteller, who read him an I Ching passage which indicated that he should destroy the heart of the problem. At that, he sent the concubine into exile and returned proper order to the court.