MacEwen played minor midget hockey with the Pownal Red Devils before joining the Charlottetown Islanders in 2012–13. As a free agent after two seasons with the Amherst Ramblers, MacEwen signed with the Moncton Wildcats of the Quebec Major Junior Hockey League. In his first full season with the team, MacEwen recorded 40 points in 66 regular season games. He attended the Anaheim Ducks training camp prior to the 2016–17 season but was returned to the QMJHL. On August 11, 2016, MacEwen was traded to the Gatineau Olympiques in exchange for their 2017 fifth round draft pick. On March 3, 2017, he signed a three-year entry level contract with the Vancouver Canucks of the National Hockey League. He later signed an amateur tryout contract with the Canucks American Hockey League affiliate, the Utica Comets, on April 10, 2017. He scored his first career AHL goal on October 29, 2017, against the Charlotte Checkers and ended his first professional season with 33 points in 66 games. He was awarded the Ian Anderson Award as the Comets Most Improved rookie. After attending the Canucks training camp, MacEwen was assigned to the Comets to begin the 2018–19 season in the AHL. He was recalled from the AHL on February 10, 2019, after a four-point game the previous night against the Rochester Americans. He subsequently made his NHL debut on February 11, 2019, against the San Jose Sharks. He recorded his first NHL point in his debut with an assist on Derrick Pouliot's goal however the Canucks lost 7–2. MacEwen was again sent to Utica to start for the 2019–20 season. He has been recalled to the Canucks several times in the 2019–20 season. On December 3, during 5–2 win over the Ottawa Senators, MacEwen scored his first NHL goal. His most recent recall to the Canucks was on January 30, 2020.
Personal life
MacEwen is of Scottish descent from his great grandmother on his father's side. While being raised in Stratford, Prince Edward Island by parents Craig and Juliana, his family ran a berry farm. On May 6, 2020, it was announced that his father Craig had died.
