The Manchester City boss becomes the first to win back-to-back gongs since Carlo Ancelotti in 2011, while the Sunderland winger impressed with five goals in three games
The Chilean guided his side to four consecutive victories in January, including a 5-1 thrashing of Tottenham at White Hart Lane and wins against Cardiff City, Newcastle and Swansea City.
Pellegrini is the first manager to win the award in back-to-back months since Carlo Ancelotti achieved the feat as Chelsea boss in 2011.
Sunderland midfielder Adam Johnson claimed the Player of the Month award for January after a sensational run of form.
The Black Cats started off the month with defeat to Aston Villa but the winger scored a hat-trick in a 4-1 win over Fulham at Craven Cottage in the following game.
Johnson struck again in a 2-2 draw with Southampton before scoring the only goal of the game in a victory over Stoke as Gus Poyet's side continue to climb up the Premier League table and away from the relegation zone.