Arriva Trains Wales was a British train operating company owned by Arriva UK Trains that operated the Wales & Borders franchise. It ran urban and inter-urban passenger services to all railway stations in Wales, including Cardiff Central, Cardiff Queen Street, Newport, Swansea, Wrexham General and Holyhead, as well as to certain stations in England such as Hereford, Shrewsbury, Chester, Crewe, Manchester Piccadilly and Birmingham New Street.

Arriva UK Trains Limited is the company that oversees Arriva's train operating companies in the United Kingdom. It gained its first franchises in February 2000. These were later lost, though several others were gained. In January 2010, with the take-over of Arriva by Deutsche Bahn, Arriva UK Trains also took over the running of those formerly overseen by DB Regio UK Limited.