Matt has been a vital member of the coaching staff for the team who originally gained promotion to Division A for the first time and had their best ever finish when they came eighth in Europe in 2011.
Matt commented: "I am happy to be given the opportunity to coach the GB under-20 team and continue the great work done in the past few years. It will be a good challenge. We have great culture from our players so I look forward to leading them in 2013."
Sarah Wagstaff will support Matt as the team manager. Sarah has extensive experience as the assistant team manager to the senior women last year.
Lee Davie has been named as the lead assistant coach and a PA coach will be added shortly.
British Basketball's Head of Performance, Warwick Cann said: "I think we have a good staff group to help drive our GB under-20 women back into Division A. The playing squad will be announced shortly as our preparation will begin in earnest in a few months"