Kennedy started in November 2009 at the US Super Tour in West Yellowstone for the first time in the Cross-Country Continental Cup and finished 69th in the 15 km freestyle. At the Nordic Junior World Ski Championships in 2011 in Otepää , he came in 50th place over 10 km freestyle, 42nd place in the skiathlon and ninth place with the relay. In December 2012 he completed his first World Cup race in Québec , which he finished in 45th place in the sprint and 23rd place in the team sprint together with Alexis Turgeon. The following month he reached the Nor-Am-Cup in Thunder Bay with the second place over 15 km freestyle his first podium in this racing series. In February 2016 he won his first Nor-Am Cup win in Prince George over 10 km freestyle. In the 2016/17 season, he came third twice and second once in the Nor-Am Cup. In addition, he won twice in Cantley and thus won the overall Nor-Am Cup ranking. At the 2018 Winter Olympics in Pyeongchang , he ran to 54th place in the sprint, 49th place in the 50 km mass start race and ninth place in the relay.
After finishing 61st in the Lillehammer Triple at the beginning of the 2018/19 season, Kennedy won the 15 km freestyle in Canmore and the 30 km mass start race in Sherbrooke . In addition, he came third twice and once in second place and thus reached fourth place in the overall Nor-Am-Cup ranking. In February 2019 he got his first World Cup points in Cogne with 12th place in the sprint. At the season highlight, the Nordic World Ski Championships 2019 in Seefeld in Tyrol , he finished 68th over 15 km classic and 46th place in the 50 km mass start race.