Geojedo or Geoje Island (also often spelled Koje Island) is the principal island of Geoje City, on the southern coast of Gyeongsangnam-do province, South Korea. It is joined to land by two bridges from nearby Tongyeong. Sinhyeon is the largest town on the island. The Busan-Geoje Fixed Link was open in December of 2010 and provides a more direct connection to the city of Busan.

Geoje Island covers an area of 383.44 km², the second largest island in South Korea (second to Jeju Island). The landscape features several peaks: Gara (580 m), Gyerong (554.9 m), the skirmisher mountain (465.5 m), Daegeum (437.5 m) and Googsabong (400 m). Geojedo is known for its rich deposits of granite. The southern belt of Geojedo, together with part of Namhaedo in Namhae County, belongs to Hallyeo Maritime National Park.

Geoje Island features several natural harbors. Shipbuilding is the largest industry on the island. The second and third largest shipyards in South Korea are both located on the island, Daewoo Shipbuilding and Marine Engineering (DSME) in the city of Okpo, and Samsung Heavy Industries (SHI) in the city of Gohyeon (Geoje City).