The Tomb of King Seongdeok () is believed to be the tomb of the Silla monarch Seongdeok (r. 702–737). It is located in what is now Gyeongju, South Korea. On January 21, 1963, it was designated Historic Site of South Korea No. 28.
The tomb is circular. It is in circumference and in height. It is surrounded by twelve badly damaged stones with carvings of animals of the zodiac. There are a number of statues near the tomb; many of these have been lost or are in poor condition. To its northwest is another tomb believed to belong to the Silla monarch Hyoso, the older brother of Seongdeok.