Casey guided the Raptors to an 8-6 record in December, including road wins over the Dallas Mavericks and Oklahoma City Thunder.
The Raptors (15-15) posted six road victories last month and have won seven of their last nine games overall. Toronto visits the Washington Wizards on Friday night.
Jeff Hornacek of the Phoenix Suns was named Western Conference coach of the month after helping the Suns to a 10-3 record over that stretch.
NEW YORK - Toronto Raptors head coach Dwane Casey was named NBA Eastern Conference coach of the month Thursday.