Changdeokgung (), also known as Changdeokgung Palace or Changdeok Palace, is set within a large park in Jongno District, Seoul, South Korea. It is one of the "Five Grand Palaces" built by the kings of the Joseon dynasty (1392–1897). As it is located east of Gyeongbok Palace, Changdeokgung—along with Changgyeonggung—is also referred to as the "East Palace" ().
Changdeokgung was the most favored palace of many Joseon kings and retained many elements dating from the Three Kingdoms of Korea period that were not incorporated in the more contemporary Gyeongbokgung. One such element is the fact that the buildings of Changdeokgung blend with the natural topography of the site instead of imposing themselves upon it. Like the other Five Grand Palaces in Seoul, it was heavily damaged during the Japanese occupation of Korea. (1910–1945). Currently, only about 30% of the pre-Japanese structures of the East Palace Complex (Changdeokgung together with Changgyeonggung) survive.
Changdeokgung was the second palace after Gyeongbokgung which had been established in 1395 as a primary palace. In the midst of strife for the throne between princes and vassals, authority of Gyeongbokgung was deteriorated. King Jeongjong enthroned by Prince Jeong-an (Yi Bang-won), who later became King Taejong, moved the capital to Gaegyeong, the capital of the Goryeo dynasty, again in 1400 on the pretext of its superior geographical features, but in fact, to avert a power struggle. King Taejong (Yi Bang-won) soon took over the throne and returned to Hanseong (present-day Seoul). Taejong was reluctant to build Gyeongbokgung Palace, which had been built by his political opponent Jeong Do-jeon, as well as being the place where he had killed his half-brothers for the throne, and therefore built new palace (named Changdeokgung). Construction of Changdeokgung began in 1405, and was completed in 1412. King Seonjo expanded the palace grounds by about 500,000 square meters, including Huwon (see below).