The territory of the Republic of Korea is the Korean Peninsula and its annexed islands, with a total area of 223,617 km² as of the end of 2020 (South Korea 100,413 km², North Korea 123,214 km²). South Korea accounts for 44.9% of the territory of the Republic of Korea. Forests occupy 63.3% of South Korea, followed by rice paddy fields (11.1%), farm fields (7.5%), roads (3.4%), and building sites (3.2%). The natural environment composed of forests and rivers (2.9%) accounts for two-thirds (66.2%) of the national land area. The land for agricultural and fishing industries, including farm fields, rice paddy fields, orchards, and ranch sites, is 19,935 km², accounting for about 20.0% of the total land area, and residential land is 3.2%.

The total length of Korea’s coastline is 15,282 km as of 2020, increasing 319 km from 2014. The natural coastline decreased by 55 km, and the artificial coastline increased by 374 km due to coastal development such as coastal reclamation, breakwater, and coastal roads. The west and the south coasts, which have a lot of terrain curvature, account for 91% of the total length of the coastline, and the east coast accounts for 9%.