The countries of Oceania are all:

here you go :)

Explanation:

As a biogeographic realm, Oceania includes all of Micronesia, Fiji, and all of Polynesia except New Zealand. New Zealand, along with New Guinea and nearby islands, Australia, eastern Indonesia, Solomon Islands, Vanuatu, and New Caledonia, constitute the separate Australasian realm. Oceania includes 14 countries: Australia, Micronesia, Fiji, Kiribati, Marshall Islands, Nauru, New Zealand, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu and Vanuatu.