The Edinburgh based club announced the signing of Milligan on Sunday (AEST) on a two-year-deal, subject to securing a work permit.
Milligan was a free agent after his contract with Saudi club Al-Ahli was sensationally terminated only six months after they signed him from Melbourne Victory in a deal believed to be worth $1 million.
The announcement ends weeks of conjecture about the 32-year-old's club future which had the midfielder linked to English clubs Bolton, QPR, and Crystal Palace after he played an influential role for Australia at the 2018 FIFA World Cup in Russia.
Despite a career spanning 16 years and nine professional clubs both in Australia and abroad, Milligan will finally get the opportunity ply his trade in a European league with many previous opportunities to move to a club on the continent throughout the years failing to come to fruition.
“I am delighted to have joined Hibernian," Milligan told the club's official website.
“I know it’s a big club with an exciting young squad, and I hope to be able to add to that with my experience.
“Jamie (Maclaren) obviously did well here last year and gave Hibs a bit of a profile back home – everyone there is pretty familiar with the Scottish game and I’m excited to now be a part of that.
“The team have had a good start to the season with the run in Europe and I’m looking forward to joining up with the squad and getting going.”
Milligan continues Hibernian's love affair with Australian players this transfer window with Maclaren also securing a second term at the club after his loan move from German parent side Darmstadt 98 was completed earlier this month.
He is Hibernian's eight signing of the transfer window with coach Neil Lennon determined to bulk up his midfield after the departure of key players John McGinn, Dylan McGeouch and Scott Allan.
Along with Maclaren, Milligan joins a host of Aussies in the Scottish Premiership with Tom Rogic and Daniel Arzani (Celtic), Oliver Bozanic, Ryan Edwards and Ben Garuccio (Hearts) and Jack Iredale (Greenock Morton).
Hibernian's next match will be at home against Ross County in the Scottish Cup on Monday (AEST).
