Determining the Southeast Asian country most similar to the South Pacific region requires considering various social, cultural, economic, and political factors. One way to answer this complex question is by analyzing the data from the Country Similarity Index. The index attempts to quantify how similar countries are to each other relative to other countries, using a variety of statistics from five broad categories: demographics, culture, politics, infrastructure, and geography.
According to the Index, the Philippines is by far the most similar Southeast Asian country to the South Pacific region. On the other end of the spectrum, Thailand has the least amount of traits in common with the South Pacific.
(South Pacific countries defined as East Timor, Fiji, Papua New Guinea, Samoa, Solomon Islands, and Vanuatu)

Although the Philippines is part of the Southeast Asia region, it has many attributes in common with countries in the South Pacific. This is especially true in terms of culture, but also government and geography as well.
Culture
The Austronesian language family connects the Philippines with several South Pacific islands, and linguistic similarities can be found among their indigenous languages. In addition, English is one of the official languages in both the Philippines and several nations in the South Pacific region. Both the Philippines and the South Pacific have a history of seafaring cultures. Traditional navigation techniques, boat building, and reliance on the sea for livelihood are common aspects. Furthermore, the majority of people in these countries are Christians. In contrast, many Southeast Asian nations are mostly Muslim or Buddhist.


Government
Countries in the South Pacific and the Philippines have democratic governments, unlike many Southeast Asian nations. Both the Philippines and South Pacific countries grapple with ethnic and cultural diversity, posing a challenge in managing this diversity within the political system. Furthermore, the Philippines and most countries in the South Pacific tend not to allow the death penalty, unlike most Southeast Asian countries which often have stricter rules.


Geography
The Philippines is a country located on many different tropical islands. Countries in the South Pacific are often located on archipelagos as well. There is a high level of seismic and volcanic activity on these islands since they are located around the Pacific Ring of Fire. Furthermore, a significant portion of the agricultural land in these countries is devoted to growing coconuts.

The Most Similar South Pacific Country to the Philippines
The Country Similarity Index suggests that Samoa is the most similar country in the South Pacific region to the Philippines. Most people in both countries natively speak an Austronesian language, but their governments also have English as one of their official languages. Like Filipinos, Samoans are mostly Christian, but they have more Protestants and less Catholics. These countries also have a similar level of development.