South Korea is located in East Asia, on the southern portion of the Korean Peninsula located out from the far east of the Asian landmass. The only country with a land border to South Korea is North Korea, lying to the north with 238 kilometres (148 mi) of the border running along the Korean Demilitarized Zone. South Korea is mostly surrounded by water and has 2,413 kilometres (1,499 mi) of coast line along three seas; to the west is the Yellow Sea, to the south is the East China Sea, and to the east is the Sea of Japan. Geographically, South Korea's landmass is approximately 100,032 square kilometres (38,623 sq mi). 290 square kilometres (110 sq mi) of South Korea are occupied by water. The approximate coordinates are 37° North, 128° East.

The Yellow Sea, also known as North Sea, is a marginal sea of the Western Pacific Ocean located between mainland China and the Korean Peninsula, and can be considered the northwestern part of the East China Sea. It is one of four seas named after common colour terms, and its name is descriptive of the golden-yellow color of the silt-ridden water discharged from major rivers.