| Masson Island | |
| Map: | Antarctica |
| Location: | Antarctica |
| Length Km: | 31 |
| Elevation M: | 465 |
| Population: | Uninhabited |
| Country: | None |
| Treaty System: | Antarctic Treaty System |
Masson Island or Mission Island is an ice-covered island about 17nmi long and rising to 465m (1,526feet), lying 9nmi northwest of Henderson Island within the Shackleton Ice Shelf. Masson Island is located in the western part of Mawson Sea at and has an elevation of 465m (1,526feet). Masson Island was discovered in February 1912 by the Australian Antarctic Expedition under Sir Douglas Mawson, who named it for Professor Sir David Orme Masson of Melbourne, a member of the Australian Antarctic Expedition Advisory Committee.