Tunapuna–Piarco is one of the 9 regions of Trinidad and Tobago. It is the most populous region in the country by total population and the fifth-largest by total land area. Geographically located in Northern Trinidad, Tunapuna–Piarco shares its borders with the regions of San Juan–Laventille to the west, Couva–Tabaquite–Talparo to the south, the Borough of Chaguanas to the south-west, Sangre Grande to the east and the Caribbean Sea to the north. The region also completely surrounds the Royal Chartered Borough of Arima, which is located in the south-eastern corner of the region.

Couva–Tabaquite–Talparo is one of the nine regions of Trinidad and Tobago, and one of the five regions which form the Gulf of Paria coastline on Trinidad's West Coast. Its regional capital and commercial center is Couva. Couva–Tabaquite–Talparo is the third-largest of Trinidad and Tobago's nine regions, with an area of 723 square kilometres (300 sq mi). As of 2011, the population was 178,410. The region is the second-most populous and fourth-least-densely populated region in Trinidad with 247 inhabitants per square kilometre (640/sq mi).