The Brecon and Merthyr Tydfil Junction Railway (B&MR) was a railway company in Wales. It was originally intended to link the towns in its name. Finding its access to Merthyr difficult at first, it acquired the Rumney Railway, an old plateway, and this gave it access to Newport docks. This changed its emphasis from rural line to mineral artery.

Thomas Savin was a British railway engineer who was the contractor who built many railways in Wales and the Welsh borders from 1857 to 1866. He also in some cases was an investor in such schemes.