Coalgate is a small town in the Selwyn District of the Canterbury region of New Zealand's South Island. It is located roughly an hour west of Christchurch on State Highway 77. The town's name stems from it being the "gateway" to the lignite coal fields around Whitecliffs, the Rakaia Gorge, and Acheron River. Coal mining declined in the 20th century and has now ceased, but since the 1950s, commercial processing of nontronite has taken place in Coalgate.