The team announced the move Thursday.
Stauskas agreed to the contract quickly after the start of free agency. Even though the NBA's offseason moratorium does not end until 12:01 p.m. EDT Friday, signings like the deal for Stauskas and the one former NBA MVP Derrick Rose completed with the Minnesota Timberwolves on Wednesday are permitted under the league's collective bargaining agreement. Short-term minimum-salary signings can be completed before the moratorium is lifted.
Portland will be Stauskas' fourth team in his five NBA seasons. He's a career 35 percent 3-point shooter.
"Nik is a versatile and talented perimeter player that will seamlessly fit into our style of play," Portland general manager Neil Olshey said.