Coalgate is a small town in the Selwyn District of the Canterbury region of New Zealand's South Island.

The town's name stems from it being the "gateway" to the lignite coal fields around Whitecliffs, the Rakaia Gorge, and The 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.

[4] Coalgate is described by Statistics New Zealand as a rural settlement, and covers 1.09 km2 (0.42 sq mi).

On 31 March 1962, the railway closed, but some of the line's old formation and the Coalgate station platform can still be found.