Walter Hahn (born 20 August 1987) is an Austrian professional wrestler and trainer.
He is currently signed to WWE, where he performs on the NXT UK and NXT brands mononymously as Walter (usually stylised in all-caps as WALTER) as the leader of the Imperium stable featuring Marcel Barthel, Fabian Aichner and Alexander Wolfe, and is the current WWE United Kingdom Champion in his first reign.
He has appeared in a number of independent promotions around the world, most notably Westside Xtreme Wrestling, Pro Wrestling Guerrilla (PWG), where he is a former one-time PWG World Champion, and Progress Wrestling, where he is a former Progress Unified World Champion.
He won the WWE United Kingdom Championship when he defeated Pete Dunne at NXT TakeOver: New York.