Map - Gyeonggi-do

Gyeonggi-do is the most populous province in South Korea. Its name, Gyeonggi, means "京 (the capital) and 畿 (the surrounding area)". Thus, Gyeonggi-do can be translated as "Seoul and the surrounding areas of Seoul". Seoul, the nation's largest city and capital, is in the heart of the area but has been separately administered as a provincial-level special city since 1946. Incheon, the nation's third-largest city, is on the coast of the province and has been similarly administered as a provincial-level metropolitan city since 1981. The three jurisdictions are collectively referred to as Sudogwon and cover 11730 km2, with a combined population of over 26 million - amounting to over half (50.25%) of the entire population of South Korea at the 2020 Census.

Gyeonggi-do has been a politically important area since 18 BCE, when Korea was divided into three nations during the Three Kingdoms period. Ever since King Onjo, the founder of Baekje (one of the three kingdoms), founded the government in Wiryeseong of Hanam, the Han River Valley was absorbed into Goguryeo in the mid-fifth century, and became Silla's territory in the year 553 (the 14th year of King Jinheung). Afterward, the current location of Gyeonggi-do, one of the nine states of Later Silla, was called Hansanju.

The Gyeonggi region started to rise as the central region of Goryeo as King Taejo of Goryeo (the kingdom following Silla) set up the capital in Gaesong. Since 1018 (the 9th year of Goryeo's King Hyeonjong), this area has been officially called "Gyeonggi".

During the Joseon, which was founded after the Goryeo, King Taejo of Joseon set the capital in Hanyang, while restructuring Gyeonggi's area to include Gwangju, Suwon, Yeoju, and Anseong, along with the southeast region. Since the period of King Taejong and Sejong the Great, the Gyeonggi region has been very similar to the current administrative area of Gyeonggi-do.

In 1895 the 23-Bu system, which reorganized administrative areas, was effected. The Gyeonggi region was divided into Hanseong (modern Seoul; Hanseong-bu; 한성부; 漢城府), Incheon (Incheon-bu; 인천부; 仁川府), Chungju (Chungju-bu; 충주부; 忠州府), Gongju (Gongju-bu; 공주부; 公州府), and Kaesong (Kaesong-bu; 개성부; 開城府).

During the Japanese colonial period, Hanseong-bu was incorporated into Gyeonggi-do. On October 1, 1910, it was renamed Keijo and a provincial government was placed in Keijo according to the reorganization of administrative districts.

After liberation and the foundation of two separate Korean states, Gyeonggi-do and its capital, Seoul, were separated with partial regions of Gyeonggi-do being incorporated into Seoul thereafter in 1946. Additionally, Kaesong became North Korean territory, the only city to change control after the countries were divided at the 38th parallel, which is now part of North Korea's North Hwanghae Province.

In 1967 the seat of the Gyeonggi provincial government was transferred from Seoul to Suwon. After Incheon separated from Gyeonggi-do in 1981, Gyeonggi regions such as Ongjin County and Ganghwa County were incorporated into Incheon in 1995.