Hussey has been appointed as the side's mentor while Harris will be supervising the bowling coach duties replacing Troy Cooley.
The former middle-order batsman's inclusion in the backroom staff is in line with the mentoring roles given to Ricky Ponting during the World Cup and Steve Waugh for the Ashes, which saw Australia retain the prized urn following a 2-2 draw.
"I'm very excited actually. I'm really looking forward to getting back in around the Aussie team," Hussey told the Sydney Daily Telegraph on Sunday.
"They are going to be trying to get strategies in place, develop a style of play and what players they want and I love all that stuff -- planning for a big event."
The 44-year-old has also hinted at the possibility of a longer association with Australia until the T20 World Cup in October 2020.
"They have floated the possibility of being involved closer to the T20 World Cup (in Australia next year) as well but it's all pretty loose at the moment," he said.
Australia will play three-match T20I series against Sri Lanka and then Pakistan to kick off their preparations for the showpiece event.
Australia, currently occupying the No. 5 spot in the Men's T20I Team Rankings, have failed to achieve a single World T20 title since the inaugural competition in 2007.
Hussey who got the title of 'Mr Cricket' due to his dogged resistance adjusted quickly to T20 cricket while fans were still wrapping their head around cricket's newborn format.
Hussey was part of Sydney Thunders team that won the 2016 Big Bash League season and was also the leading run-scorer in the Indian Premier League 2013 edition - which is a testament to his sheer batting genius.
He has a phenomenal track record across all formats of the game and who can forget the mesmerizing win back in 2010 during the T20 World Cup Semifinal in which Hussey single-handedly took the game away by smashing 60 off 24 balls and slugged Saeed Ajmal's off-spinners and doosras out of the park for maximums in his last over. And now he will be guiding the current crop of players on how to get the better of Asian powerhouses.
Ryan Harris, the former frontline pacer of Australia, was a late bloomer as he made his debut at the age of 29, stymied by some gruelling injuries throughout his career but whatever amount of cricket he played, it was top-drawer. The highly skilful bowler was a precious commodity in the Test format and was the player of the series in Ashes 2013 where he shed 24 wickets during the riveting Test match battle.
It is part of Justin Langer's vision to involve the greats of Australia cricket with the national team players: "I can't tell you how influential these guys can be on the group. It's about building our leadership, about honing their skills as cricketers, and they can just complement the other guys who are full-time coaches."
First T20: October 27, Adelaide Oval
Second T20: October 30, Gabba
Third T20: November 1, Melbourne Cricket Ground
First T20: November 3, Sydney Cricket Ground
Second T20: November 5, Manuka Oval
Third T20: November 8, Perth Stadium
Aaron Finch (c), Ashton Agar, Alex Carey, Pat Cummins, Glenn Maxwell, Ben McDermott, Kane Richardson, Steve Smith, Billy Stanlake, Mitchell Starc, Ashton Turner, Andrew Tye, David Warner, Adam Zampa.
Lasith Malinga (c), Kusal Perera, Kusal Mendis, Danushka Gunathilaka, Avishka Fernando, Niroshan Dickwella, Dasun Shanaka, Shehan Jayasuriya, Bhanuka Rajapaksa, Oshada Fernando, Wanindu Hasaranga, Lakshan Sandakan, Nuwan Pradeep, Lahiru Kumara, Isuru Udana, Kasun Rajitha.
Pakistan Squad for the T20I series will be announced on 21st October.