King Jeonggang of Silla (Hanja: 定康王; Born: circa 863 - Died: 887; Reigned: 886–887), whose born as Kim Hwang (김황/金晃) was the 50th ruler of the Korean kingdom of Silla. He was the second son of King Gyeongmun; his siblings included his predecessor King Heon-gang and his successor Queen Jinseong. Jeonggang rose to the throne when his brother Heon-gang died without an heir. He followed his brother's example less than two years later. In his final year, he put down the rebellion of Kim Yo.
However, he reigned only for a year before he died from a disease. On his deathbed, King Jeonggang said his last words, "Unfortunately I don’t have any offspring to succeed the throne. Therefore, I order my throne to be succeeded by my sister, Man, following the suit of Queen Seondeok and Queen Jindeok." His sister, Kim Man, is the 51st monarch of Silla Dynasty, Queen Jinseong.
King Jeonggang's tomb in Namsan-dong san 53-beonji, Gyeongju, Northern Gyeongsang is a circular grave mound surrounded by three layers of piled cut stones at the bottom of the perimeter in order to prevent the mound from collapsing. The bottom layer is projected slightly forward like ground stone, and the two upper stages are piled up slightly inward. Except for the stone-made small altar in front of the tomb, there is no additional decoration or stone statue. The way the tomb was piled up with an embankment at the bottom of perimeter is very similar to that of King Heon-gang.