King Heungdeok of Silla (Hanja: 興德王; Born: 777 - Died: 836; Reigned: 826–836) who known as Kim Gyeong-hwi (김경휘/金景徽) during his teenager days; Kim Soo-jong (김수종/金秀宗) and Kim Soo-seung (김수승/金秀升) during his childhood was the 42nd ruler of the Korean kingdom of Silla. He was the younger brother of King Heondeok. He was married to Queen Jeongmok, the daughter of King Soseong.
Upon rising to the throne, Heungdeok made Kim Yu-jing his prime minister (sijung) and appointed General Jang Bogo to the command of the Cheonghaejin Naval Headquarters in Wando County, Southern Jeolla Province. Jang later used this as a basis for dominating Silla politics through the mid-9th century. In his reign, tea was first introduced into Korea from Tang China and was planted on Mount Jiri, the second highest mountain in Korean Republic after Mount Halla.
In 834, the king revised the colors of official dress. He also issued an edict forbidding "excessive luxuries" to the common people. Two years later, Heungdeok died without an heir. He was buried in Yuktong-ri san 42-beonji, Angang-eup, Gyeongju City, Northern Gyeongsang Province, South Korea.
The Royal Tomb of King Heungdeok is one of the best preserved among Silla tombs. Twelve zodiac images are engraved on the side stones of the huge round mound, four sculptured stone lions are at the four corners of the square stone pavement around the mound, and stone figures of civil and military officers stand on both sides of the passageway leading to the tomb.
The tomb served as a model for all succeeding tombs of the Unified Silla Era. Some broken pieces of a tomb stele stating that this is the tomb of King Heungdeok were found near the mound. A tortoise pedestal on which the tomb stele originally stood remains in front of the tomb.