I enjoyed Karl Henrikkson's list "10 books set in Asia" - and so I came up with a list of 10 books set in Oceania:
Australasia: Includes Australia, New Zealand, and nearby islands.
Melanesia: Located north-east of Australia, this includes countries like Papua New Guinea and Fiji.
Micronesia: Situated to the north of Melanesia, this region includes the Marshall Islands and Kiribati.
Polynesia: This includes a vast triangle of islands in the central Pacific, with notable countries being Samoa, Tonga, and Tuvalu.