Mapo District (Korean: 마포구; RR: Mapo-gu) is one of the 25 districts of Seoul, South Korea. Mapo has a population of 381,330 (2015) and has a geographic area of 23.87 km² (9.22 sq mi), and is divided into 24 dong (administrative neighborhoods). Mapo is located in western Seoul on the northern bank of the Han River, bordering the Gyeonggi Province city of Goyang to the northwest, and the Seoul city districts of Gangseo to the west, Yeongdeungpo to the south, Yongsan to the southeast, Jung to the east, and Seodaemun and Eunpyeong to the north.

Mapo is home to several universities and government buildings, and is well known for the Hongdae club district around Hongik University. Mapo is connected to the Seoul Metropolitan Subway's Line 2, Line 5, and Line 6, as well as the Airport Railroad, and the Korail Gyeongui-Jungang Line, which all pass through this district. The Seoul World Cup Stadium, a famous landmark in Seoul, is located in Sangam in northwest Mapo.

The name "Mapo" comes from the name of an old ferry across the Han River, and can roughly be translated as "hemp ferry." Historically, Mapo was a significant ferry terminal of the Han River that facilitated transportation and commerce, especially of goods coming from the provinces in the south. Its geographical location rendered it one of the major landing points for grain and seafood during the Joseon Dynasty.

Mapo-gu’s historical roots can be traced back to the early Joseon Dynasty when the area fell under the jurisdiction of Hanseongbu, the capital administration. Though it lay within a short distance—about 10 li—from the city walls, it had not yet been formed into an independent administrative district. Later in the Joseon period, Hanseongbu expanded to include five new administrative regions: Dumobang, Hangangbang, Dunjibang, Yongsanbang, and Seogangbang. Parts of present-day Mapo-gu became included within the boundaries of Yongsanbang and Seogangbang.

During the Joseon period, Mapo held geographical and economic significance due to its location along the Han River. It served as a key river port and ferry crossing, situated near Ha-joongdo (modern-day Yeouido), linking to inland routes that led to places such as Siheung. Mapo was one of the “Five Ports of the Han River” (오강, 五江), alongside Ttukseom, Noryang, Yongsan, and Yanghwajin. These ports were central to unloading, storing, and redistributing goods that traveled via the Han River, which served as a vital transportation route through central Korea. Mapo, along with Yongsan and Yanghwajin, handled large quantities of grain from the southern provinces, as well as seafood like shrimp and croaker brought in from the Yellow Sea, making it a key hub in the redistribution of agricultural and marine products.

A major administrative shift occurred in 1910 under Japanese colonial rule. Hanseongbu was renamed Gyeongseongbu and placed under Gyeonggi-do’s authority. The following year, it was granted official administrative status through Gyeonggi-do’s ordinance. During this reorganization, Yongsanbang and Seogangbang were reclassified as Yongsan-myeon and Seogang-myeon, each overseeing numerous small districts.

Mapo's position as a transportation and commerce hub continued through the early years of the 20th century. In 1910, the first streetcar line of Seoul was extended from Seodaemun to Mapo, and it became an even more accessible and important ward. The new infrastructure heightened its role as a distribution point, particularly for seafood. But with the devastation of the streetcar system and closure of Han River transportation routes during the Korean War and peninsula division, Mapo lost much of its historical role as a hub of movement and commodity redistribution.

In 1913, another reorganization placed much of what we now consider Mapo-gu into the western portion of Gyeongseong-bu, while Seogang-myeon was incorporated into Goyang-gun, also within Gyeonggi Province. Over the next decades, administrative boundaries were adjusted several times. A significant development came on October 23, 1944, when parts of Seodaemun-gu and Yongsan-gu were separated to formally establish Mapo-gu as an independent district.