The 10-time NBA All-Star has not played since November 8 last year with the Houston Rockets. Houston traded him to Chicago on January 22 and the Bulls waived him on February 1.
“Carmelo is an established star in this league that will provide a respected presence in our locker room and a skill set at a position of need on the floor,” said Blazers president of basketball operations Neil Olshey.
Anthony, 35, holds career NBA averages of 24.0 points, 6.5 rebounds, 3.0 assists and 1.02 steals in 1,064 games (1,056 starts) over 16 seasons with Denver, New York, Oklahoma City and Houston.
He also won three Olympic gold medals with Team USA in 2008, 2012 and 2016.
The Blazers granted Anthony’s request to return to the league in uniform number 00 and he is expected to appear off the bench with Portland’s second unit.