Curran is the first 100+ gamer in the NRL to commit himself to Mal Meninga's side, which will enter the competition as the 18th club from 2027.
His ability to play multiple positions, including back row and prop, was seen as a vital asset as Meninga looks to build a flexible side that can hit the ground running from Round 1.
In a club statement, Meninga hailed Curran's "unique combination of skill and finesse with the ball".
"He plays with intensity and a commitment to make his teammates shine," Meninga added.
"I couldn't be more impressed with Josh off the field, too. He is a leader who spends countless hours investing back into the community."
That community-minded spirit will be especially important for the Bears as they look to engage with a brand new market that has not had an elite level rugby league club since the short-lived Western Reds of 1992 to 1997.
It was the opportunity to win over thousands of new supporters in a city of more than 2.3 million people that attracted Curran to the project.
"This is an exciting opportunity that I just couldn't pass up," Curran said.
"The chance to be a part of the Bears' inaugural squad, to have my name as one of their first signings, is surreal.
"I'm passionate about getting out in the community, and to have the opportunity to create something from the ground up that can inspire a whole state also motivates me.
"This is history for our game, and I'm super excited to be a part of it."
Perth Bears inaugural squad:
Emarly Bitungane (London Broncos), Josh Curran (Canterbury Bulldogs), Iszac Fa'asuamaleaui (Catalans Dragons), Liam Henry (Penrith Panthers), Harry Newman (Leeds Rhinos), Sean Russell (Parramatta Eels), Toby Sexton (Catalans Dragons), Luke Smith (London Broncos)