Who wins NBA Coach of Year?

Joe Mazzulla wins NBA Coach of the Year

Boston Celtics coach Joe Mazzulla won the 2025–26 NBA Coach of the Year Award, according to multiple reports. His finalist competition included J.B. Bickerstaff and Mitch Johnson.

The significance is tied to what the award reflects: sustained performance and team development over the course of the season. The coverage frames Mazzulla’s run as a major success, highlighting that Boston’s record hit a high point—56 wins—and that his work went beyond raw wins total.

In particular, the story emphasis is that the Celtics’ development and execution improved under Mazzulla’s leadership, not just that the team recorded victories. That kind of framing is common with Coach of the Year selections, because it recognizes coaching impact on players’ growth, adjustments across the season, and competitiveness in different game situations.

For Bickerstaff and Johnson, the news also clarifies the top-of-mind coaching narrative for the league’s awards cycle: they were considered among the best and were left just short by the voting.

For fans, the award cements Boston’s credibility as a system-driven team rather than one built only on individual talent. It also underscores why the Celtics remain one of the most respected organizations in the NBA’s current landscape going into the next postseason.