| Gasi Oreum | |
|---|---|
 View from base (2026) | |
| Highest point | |
| Coordinates | 33°14′48″N 126°14′37″E / 33.2468°N 126.2436°E |
| Geography | |
 | |
| Korean name | |
| Hangul | 가시오름 |
| RR | Gasioreum |
| MR | Kasiorŭm |
Gasi Oreum (Korean: 가시오름) is an oreum (small extinct volcano) in Daejeong-eup, Seogwipo, Jeju Province, South Korea. It has an elevation of 106.5m, height of 77m, circumference of 1,874m, and area of 263,863m2.
The mountain goes by a variety of names, including Gasireum (가시름), Gasiak (가시악; 加時岳), and Ipak (입악; 笠岳). The term gasi in the hill's name, means thorn, and refers to the numerous thorny plants that grow on the hill.
The hill has a hiking trail on it. It has been described by several writers as a fairly easy hike, in part owing to the hill's small height and size.