The 23-year-old Canberra junior has signed a two-year deal with Irish club Connacht in a move the province's coach Andy Friend has hailed as "a real coup".

Hansen will leave the Brumbies at the end of the Super Rugby season having risen through the club's junior pathways since coming through Daramalan College.

The loss of Hansen, whose mother hails from Cork, will be a cruel blow for the Super Rugby AU championship contenders who will bid farewell to a club junior and one of their most exciting young talents.

But Hansen, who has impressed during the Brumbies' domestic campaign so far this season, has his sights set on a return to the capital following his overseas stint.

MORE SPORT

"The opportunity to be able to travel the world and continue to play the game I love overseas was one that was difficult to turn down and I hope to be back playing here in Canberra in the future," Hansen said.

"Having an experience outside of Canberra, not just as a rugby player but as a person as well is something I'm excited about but I'll be keeping a keen eye on how the boys go back home and hope to be back one day.

"I'd firstly like to thank everyone involved at the Brumbies and in the ACT Rugby community for giving me the opportunity to live out my boyhood dream representing this club.

"As a proud Canberran all I ever wanted was to pull on the Brumbies jersey and to be able to represent our region."

Places in the Brumbies' starting XV are hard to come by with a host of players with Test caps in the back line, though Hansen has rarely put a foot wrong when given a chance.

Hansen made his Brumbies debut off the bench against the NSW Waratahs in 2019 but his highlight to date would be slotting a match-winner against Queensland last year.

Friend says he has been keeping an eye on Hansen's rise in recent years and believes his playmaking abilities and size will mean he can easily adjust to the northern hemisphere style.

Brumbies coach Dan McKellar admits it will be tough to see Hansen leave the club, with the rising star to link up with Connacht for pre-season training later this winter.

"We're really disappointed Mack won't be at the club next season but understand his desire as a young man to want to see the world and experience a new culture," McKellar said.

"It's one of the real advantages of our international game and I'm sure Mack will continue to grow as a player and person through that experience.

"He's a real character of our squad and no doubt will be missed by the team and the organisation and we really hope to see him back at the Brumbies in the not too distant future."