What is the most populous island in Samoa?

Upolu is the most populous island in Samoa. It has about 145,000 inhabitants, far more than Samoa’s other main island, Savaiʻi.

Upolu is approximately 75 kilometres long and covers about 1,125 square kilometres. It is the second-largest Samoan island by area, after Savaiʻi, but population is concentrated on Upolu because it contains Apia, Samoa’s capital and largest urban centre. Apia sits on the island’s north coast and is the country’s main administrative, commercial and transport hub.

Geologically, Upolu formed from a massive basaltic shield volcano rising from the western Pacific seafloor. Its highest point is Mount Vaivai, reaching roughly 1,113 metres. The island’s landscapes include volcanic uplands, tropical forests, villages and coastal lagoons.

The main trap in this question is confusing population with size. Savaiʻi is the larger island by land area and is often called Samoa’s “big island,” while Upolu is the more densely settled and populous one. Viti Levu is Fiji’s largest and most populous island, and Guadalcanal belongs to Solomon Islands, not Samoa.