Dumai, is a coastal city in Riau Province on the island of Sumatra, Indonesia. The city has an area of 2,066.72 km2 and had 331,832 inhabitants at mid 2022 official estimate. Dumai has a domestic airport, Pinang Kampai Airport. Dumai is an important transport and trade centre, both regionally and internationally, especially to Malaysia. Dumai is rich in oil.

Riau is a province of Indonesia. It is located on the central eastern coast of Sumatra along the Strait of Malacca. The province shares land borders with North Sumatra to the northwest, West Sumatra to the west, and Jambi to the south, and a maritime border with the Riau Islands and the country of Malaysia to the east. It is the second-largest province in the island of Sumatra after South Sumatra, and is slightly larger than Jordan. According to the 2020 census, Riau had a population of 6,394,087 across a land area of 89,935.90 km²; the official estimate of population as of mid-2022 was 6,614,384. The province comprises ten regencies and two cities, with Pekanbaru serving as the capital and largest city.