King Ilseong of Silla (died 154, Reigned: 134–154) was the seventh ruler of Silla, one of the Three Kingdoms of Korea. He is commonly called King Ilseong-Isageum (Hanja: 逸聖泥師今), where the 'isageum' being the royal title in early Silla. As a descendent of Silla's founder King Hyeokgeose-Geoseogan, his surname was Park.
Reports differ as to whether he was the eldest son of King Yuri, or perhaps a more distant relative. Modern scholars believe he was likely the grandson of Yuri. He married a princess of the Park clan.
He created bureaucratic offices and built a central administrative building. He ordered the cultivation of new agricultural fields. He is primarily remembered for his 144 edict banning the use of jewelry and other luxury goods by the populace. During his reign there were several invasions by the northern Malgal tribes. In 146, he suppressed a rebellion by a tributary state in present-day Gyeongsan, Northern Gyeongsang Province. The tomb of King Ilseong-Isageum is located in Tap-dong san 23-beonji, Gyeongju City, Northern Gyeongsang.