The 14-year NBA veteran was limited to just one game last season because of injuries but came through this year with 16.9 points and 3.1 assists per game in eight contests. Each ranked among the top five in the league, per the BIG3 official site.
Maggette was also named Captain of the Year as he tries to lead his squad to a championship in Friday's final.
Although the 38-year-old had never won an award in the NBA and was never named an All-Star, his second career seems to be going well.
Among the other notable award winners, Gary Payton was named the top trash-talker.
Payton had also been known as an elite trash-talker through his Hall of Fame career, and that hasn't stopped in the three-on-three tournament, as he showed in July:
Chris "Birdman" Andersen was named the Defensive Player of the Year after leading the league with 1.4 blocks per game, while the league's leading scorer at 18.0 points per game, Al Harrington, was called Too Hard to Guard.
Power, which features Maggette as well as Cuttino Mobley and Glen Davis, will take on 3's Company for the championship, a squad that includes DerMarr Johnson and Baron Davis.