Ellis averaged 25.7 points, 4.7 assists and 4.0 rebounds over three games to help Dallas secure a playoff berth.
Dirk Nowitzki and Ellis became the first teammates in Mavericks history to win back-to-back Player of the Week honors. Nowitzki took home the award last week.
Teague led the Hawks to a 3-1 record, averaging 20.3 points, 5.8 assists and 1.75 steals to aid Atlanta in clinching a playoff berth for the seventh straight season.
Other nominees included Brooklyn's Mason Plumlee, Charlotte's Al Jefferson, Chicago's Joakim Noah, Denver's Kenneth Faried, Golden State's Stephen Curry, Indiana's Paul George, Oklahoma City's Kevin Durant, Portland's LaMarcus Aldridge and Phoenix's Eric Bledsoe.