Waegwan (Korean: 왜관; Hanja: 倭館; lit. Japanese house; pronounced [wɛgwan]), also known as wakan (Japanese: 和館; Hir: わかん), were Japanese ethnic enclaves (nihonmachi) primarily located in southern coastal cities of the Koreanic state Joseon. They existed from around the 15th century until the late 19th century. Along with general Japanese trade with Korea they were managed by the Tsushima-Fuchū Domain of Azuchi–Momoyama and Edo periods.

In the middle Joseon period they served as important trading hubs. In the late Joseon period, the only remaining waegwan in Busan became de facto extraterritorial enclave, as Japanese diplomats were forbidden to negotiate in Seoul.

Unlike the Ming dynasty's policy of haijin (restricting maritime trade), Korea permitted free entry of ships into its ports. As a result, trade between the Joseon and Japanese feudal lords increased rapidly. When Joseon harbors became targets for wokou pirates, in 1407, King Taejong restricted Japanese ships to the ports of Busan, Naei, and Yeom. By 1410, all forms of Japanese communication, including entrance of envoys and messengers, known to Koreans as Chŏbwae (접왜; 接倭), were also restricted to these ports. Originally intended only as a stop for Japanese ships, these ports soon became hotspots for Japanese residents and their families, primarily arriving from Tsushima Island, forming the first waegwan ethnic enclaves called sampo (삼포; 三浦; lit. three ports).

In 1419, the Ōei Invasion by wokou pirates forced the sampo waegwan to shut down, but they were soon re-opened. Over time, Japanese residents who were not naturalized Korean citizens became known as kokyowa (恒居倭, 'permanent Japanese'), and titles like atama (頭, 'head') were given to waegwan leaders. Due to overpopulation some kokyowa lived outside of waegwan boundaries, intermingling with local Korean villagers and engaged in fishing and agriculture, some in smuggling. Joseon attempts to monitor these residents, such as sending Korean officials to keep watch over daily merchant activities often failed. Taxation attempts also yielded mixed results forcing Korean authorities to put more pressure on the kokyowa.

When King Jungjong of Joseon succeeded his half-brother Yeonsangun to the throne in 1506, the Korean government implemented reforms that included the elimination of tax breaks for Japanese citizens. Tensions climaxed during the Disturbance of the Three Ports, when Japanese nationals and the ruling Sō clan of Tsushima captured Naei port and held its mayor Kim Sae-gyun (김세균; 金世鈞) hostage. The rebellion was quickly stamped out and King Jungjong ordered the shutdown of the sampo waegwan, though they would be reopened after the Treaty of Imsin [ko; ja]. Diplomacy between Japan and Korea would be officially severed following Hideyoshi Toyotomi's invasion of Korea in 1592, leading to the permanent end of the sampo waegwan.

The waegwan of Busan-po (부산포; 富山浦) was located in present-day Dong District of Busan. It was the oldest of the sampo waegwans; about 450 Japanese lived there in 1492. It was shut down in 1510 but was reopened in 1521, and existed until the invasions of Korea in 1592. Although two new waegwans would be established in Busan, the site of the old Busan-po waegwan would be subsumed into a prefectural military base.

The waegwan of Naei-po (내이포; 乃而浦) was located in present-day Jinhae-gu District of Changwon. The Japanese population in Naei was largest of all waegwan reaching over 2,500 in 1494. An attempt was made by the Joseon to deport excess Japanese, but the numbers rebounded. Naei was hit hardest in the Disturbance and was shut down in 1510 but was reopened in 1521; it was closed again due to the Jiajing wokou raids in 1544 during the Treaty of Chŏngsa [ja] (정사약조; 丁巳約條) and was never reopened.

The waegwan of Yeom-po (염포; 鹽浦) was located in present-day Jung District in Ulsan. Located on the south bank across the bay from Ulsan's old town, it was re-opened in 1426 following the Oei Invasions, with 150 Japanese living by 1494; after the Disturbance, the waegwan closed in 1510 and never reopened.