Gasol, 39, joins a reshaped Blazers roster that is prepared to make a run at a return to the Western Conference finals -- and perhaps beyond.
On Twitter, Gasol said he is enthused to join the Blazers.
Gasol brings the résumé of a future Hall of Famer as compiled across 18 NBA seasons, including two championships and six All-Star appearances.
He signed with the Milwaukee Bucks after a buyout with the San Antonio Spurs last season but played only three games with Milwaukee before a season-ending foot injury. Gasol finished the campaign having played just 30 games, averaging a career-low 3.9 points and 4.6 rebounds.
Gasol discussed a free-agent deal with the Blazers in 2016 before signing with San Antonio.