Kevin Durant of the Oklahoma City Thunder took the Western Conference honour.
DeRozan and Lowry led the Raptors to 12-2 record in January. Toronto finished the month on a franchise-record 11-game winning streak.
DeRozan ranked second among Eastern Conference players last month with a scoring average of 23.9 points per game. He had a .417 shooting percentage from three-point range and shot at an .848 clip from the free-throw line.
Lowry, meanwhile, finished seventh in East scoring last month with an average of 21.7 points per game. He was the only player in the conference to record at least 300 points, over 90 assists and over 30 steals in January.