The 28-year-old Australia international joins ahead of Saturday’s season curtain-raiser at Watford, having passed his medical at the American Express Elite Football Performance Centre earlier today.
Head coach Graham Potter commented, “We are delighted to welcome Aaron to the club. He has played very well over the past two seasons in the Premier League, and will bring a different option and added competition to our midfield.
“He’s been a talisman for Huddersfield in recent seasons with his performances on the field; and he’s proved to be an excellent professional both on and off the pitch.
“I’m looking forward to working with him, and he is another good addition to our squad ahead of the new season.”
Mooy was born in Sydney, and initially moved to England and Bolton Wanderers in 2006, joining their academy as a teenager. After two years with Bolton, at 18 he left to join SPL side St Mirren, to play senior football.
After two seasons in Scotland, a four-year spell back in Australia followed. That saw stints with Western Sydney Wanderers and Manchester City’s sister club Melbourne City.
His form at the latter saw him win the Australian PFA Player of the Year. That prompted a move to England and to the Etihad to join City in 2016.
He was immediately loaned to Huddersfield, and in his first season helped the Terriers win promotion to the Premier League — alongside Albion — and was named in the PFA and EFL Championship teams of the season.
That prompted Huddersfield to make the move permanent, and Mooy was Town’s standout performer during their two-year stay in the top flight.
He is an international teammate of Mat Ryan, having made his senior debut for Australia in 2012, and has won 39 caps and scored five goals for the Socceroos.