After struggles by Cubs closer José Veras early in the 2014 season, Rondón was named the new Cubs closer. He had a breakout 2014 season. He earned two saves in the 2015 National League Division Series against the St. Louis Cardinals, including a save in the series-clinching game 4. With the addition of Aroldis Chapman in late July 2016, Rondon was moved to the setup role in the bullpen. Rondon finished 2016 with a 2-3 record and a 3.53 ERA in 54 appearances. The Cubs won the 2016 World Series over the Cleveland Indians, ending the Cubs' 108-year drought. He was non-tendered and became a free agent on December 1, 2017.