The Queensland Railways B15 class locomotive is an old class of 4-6-0 engines operated by the Queensland Railways.

In 1889 the first B15 class locomotives built by Nasmyth, Wilson & Co entered service.

Further orders from Evans, Anderson, Phelan & Co, Yorkshire Engine Company and Walkers Limited saw the class total of 92 engines by 1899.

Per Queensland Railway's classification system they were designated the B15 class engine, B representing they had three driving axles, and 15-inch (381 mm) diameter cylinders.

A further six engines were acquired In 1919 when the Queensland Railways took over the Chillagoe Railway & Mining Co.[1][2][3] Problems with broken rails saw three sets of 45-inch (1,143 mm) driving wheels acquired from the South Australian Railways and fitted to 336 at North Ipswich Railway Workshops in November 1900.