Cooper joined John Tortorella as the only coaches in franchise history to record 200 wins. On January 7, 2018, Cooper was named as head coach of the Atlantic Division for the 63rd National Hockey League All-Star Game, which was played at Amalie Arena in Tampa, Florida. The selection was because the Lightning were the team with the highest points percentage in the Atlantic Division. On March 30, 2018, Cooper recorded his 240th career NHL win against the New York Rangers at Madison Square Garden. The win moved Cooper past John Tortorella for most wins in franchise history. On January 5, 2019, Cooper was named to the 2019 National Hockey League All-Star Game. This was Cooper's second consecutive selection to the NHL All-Star game. On March 18, 2019, Cooper coached the Lightning to their first Presidents' Trophy in franchise history with a victory over the visiting Arizona Coyotes at Amalie Arena. On March 21, 2019, Cooper recorded his 300th career NHL win in a 6–3 Lightning win over the Carolina Hurricanes at PNC Arena. On March 26, 2019, Cooper signed a multi-year contract extension to remain as the head coach of the Lightning. On April 1, 2019, Cooper coached the Lightning to their 60th win of the season. With the win, the Lightning became only the 3rd team in NHL history to reach the mark and Cooper became the second coach in NHL history to reach the mark. Cooper's Tampa Bay Lightning that season were then swept in the first round by the Columbus Blue Jackets, making them also the first team to win the President's Trophy to not win a single post-season game. On November 13, 2015, Team North America general manager, Peter Chiarelli, named Cooper as an assistant coach for the 2016 World Cup of Hockey. Cooper served as an assistant coach with Peter DeBoer, Dave Tippett and Jay Woodcroft under Team North America head coach Todd McLellan. On April 11, 2017, Hockey Canada named Cooper as the head coach of Canada's men's national ice hockey team for the 2017 IIHF World Championship tournament. Cooper was joined by assistant coaches Gerard Gallant, Dave Hakstol, and Dave King. On May 21, 2017, Cooper coached Team Canada to a silver medal. Team Canada lost to Team Sweden 2–1 in a shootout. * – Mid-season replacement