Ilseong (died 154, r. 134–154) was the seventh ruler of Silla, one of the Three Kingdoms of Korea. He is commonly called Ilseong Isageum, isageum being the royal title in early Silla. As a descendant of Silla's founder Hyeokgeose, his surname was Bak.

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.^[1] He married a princess of the Bak clan. and he was an older brother of Pasa

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.^[2] In 146, he suppressed a rebellion by a tributary state in present-day Gyeongsan, North Gyeongsang Province.

The tomb of King Ilseong is located in Tap-dong, central Gyeongju.

• Grandfather: King Namhae of Silla
• Grandmother: Lady Unje (알영부인)
• Father: Yuri Isageum?
• Mother: Queen Ilsaeng (이리생부인)
• Wife:
  • Queen Park, of the Park clan (모후 박씨) daughter of Jisorye Wang (지소례왕)
    • Son: Adalla of Silla (died 184, r. 154–184)

• Three Kingdoms of Korea
• Rulers of Korea
• History of Korea

• Korea Britannica