The MRWA B class was a class of steam locomotives built by Hawthorn Leslie in Tyneside, England, for the Midland Railway of Western Australia (MRWA).

Withdrawals began in 1929, but the five longest serving units continued working on the MRWA, mainly as shunting engines, from then until the 1950s.

[2] In 1995, ownership of B6 was transferred to the then Shire of Swan, and in 1999 the locomotive was moved to the former Midland Railway Workshops, for storage in the custody of Rail Heritage WA.

[2] In 2010, following a renewal of interest by the City of Geraldton-Greenough in rail history, B6 was moved back to the Geraldton area, for intended eventual display at a proposed railway museum at Walkaway.

[3] Media related to MRWA B class at Wikimedia Commons