Suarez started and ended the month on a sour note, with defeats at Hull City, Manchester City and Chelsea, but was in blistering form for the four intervening matches, scoring 10 goals.
Those inlude four in one match against Norwich City on December 4, two against West Ham, two in a superb performance at Tottenham which spelled the end for Andre Villas-Boas at White Hart Lane, and two against Cardiff City.
Those goals helped put the Reds top of the Premier League table on Christmas Day, although they had slipped to fifth by New Year's Eve.
Pellegrini has been recognised as December's best manager after guiding his side to an unbeaten month, with six wins from seven games.
Southampton were the only side to stop City winning last month, claiming a 1-1 draw at St Mary's. But victories against Swansea, West Brom, Arsenal, Fulham, Liverpool and Crystal Palace make the Chilean the obvious choice.
Those results leave City just one point behind table-toppers Arsenal, who were beaten 6-3 at the Etihad Stadium on December 14.