The NZR BC class comprised a single steam locomotive that operated on New Zealand's national rail network.

It entered service on 10 June 1902 and was at the time the most powerful locomotive to operate in the country.

It was a Vauclain compound, and its trailing truck bore similarities to the Q class, the world's first 4-6-2 "Pacific" type then under construction by Baldwin for NZR.

This line became the southern portion of the North Island Main Trunk Railway when acquired by NZR in 1908.

A decade after it was withdrawn, the steepest section of its former line was bypassed by the Tawa Flat deviation and became the Johnsonville Branch.