The deadline day switch was finalised just as the transfer window was closing at 2am today after he passed a medical and the paperwork was completed.

"We are delighted to welcome Aaron to the club," said head coach Graham Potter. "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.”

Goalkeeper Ryan has been with Brighton since their promotion to the top flight in 2017.

Mooy had been linked with several Premier League teams following Huddersfield Town's relegation to the Championship.

Fellow south coast team Bournemouth, along with Newcastle United and West Ham, have all been interested in Mooy during the off-season.

Despite the reported interest, the 28-year-old played a full match for the Terriers' in their season-opening 2-1 loss to Derby County on Tuesday, but will now be in the mix for this weekend's season opener for Brighton against Watford.

In other Socceroos-related transfer news, midfielder Massimo Luongo has sealed a move from Queen's Park Rangers to fellow Championship club Sheffield Wednesday.

The 26-year-old, who didn't feature in QPR's opening weekend victory against Stoke City, has joined Wednesday on a three-year deal for an undisclosed fee.

Meanwhile, former Socceroos captain Mile Jedinak is still without a club after the 35-year-old was released by Aston Villa at the end of last season.