He currently coaches GB under-20 player and British Basketball Emerging Player of the Year 2012 winner, Alasdair Fraser, where Fraser was also named to the All-America East Third Team.
Leichner will lead the GB under-20 men at the European Championship which takes place in Romania from the 11-21 July 2013.
Leichner commented on his appointment: "I am privileged and humbled to have the opportunity to coach the Great Britain under-20 men's team with the ultimate goal of winning a European Championship.
"I would like to thank British Basketball for this honoured appointment and look forward to leading a great group of young men at the European Championships."
Before working with Maine, Leichner coached the professional Irish club, UCC Demons in Cork. The 2008-2009 season proved to be an unprecedented campaign as the UCC Demons won the "Treble" for the first time in Irish basketball history. As a result of his team's success, Leichner was named "SuperLeague Coach of the Year 2008-09", "Eurobasket.com Ireland Coach of the Year 2008-09" and "Streetball Ireland Coach of the Year 2008-09".
James Vear an up and coming British coach who coached Medway Park EBL Div 1 men's side has been announced as the assistant coach. Long time incumbent Mark Lloyd will be the manager. Five of last year's team are eligible to return this season.
British Basketball's Head of Performance, Warwick Cann added: "We are delighted to have Douglas on board as the head coach. With his experience he is very familiar with the under-20 European Championships and has extensive knowledge of our British players which will be an asset for the team and its goals this season."