The late Bill Russell is getting the ultimate tribute -- the NBA just announced the Celtics legend's No. 6 will be retired throughout the league ... making him the first player to receive such an honor.
The Association just announced the move minutes ago ... with commish Adam Silver explaining the decision.
"Bill Russell's unparalleled success on the court and pioneering civil rights activism deserve to be honored in a unique and historic way," Silver said. "Permanently retiring his No. 6 across every NBA team ensures that Bill's transcendent career will always be recognized."
Current players who don the number -- most notably Lakers superstar LeBron James -- will not have to make a change ... as the league says those who currently wear No. 6 will be grandfathered.
On top of the number retirement, the league says each player will wear a jersey patch honoring the 11-time champion ... and each court will display a tribute logo next to the scorer's table.
The honor is exactly what names like Magic Johnson and Mike Woodson were hoping for -- both former players called for the league to raise No. 6 in the rafters at every NBA arena.
Russell passed away last month. He was 88 years old.