Starting next May, WestJet will fly to the two cities four times a week from Toronto Pearson airport.
WestJet said its Glasgow and Cardiff routes would serve as meaningful connections "to underserved markets rich in culture, community and opportunity".
It will operate the routes using Boeing 737 Max aircraft; Glasgow will take off on 15 May 2026 followed by Cardiff on 23 May 2026.
WestJet launched flights to Glasgow in 2015, becoming the first UK airport it operated from. It last served Glasgow in 2022.
Its new Cardiff route, meanwhile, will be Wales's first direct air connection with Canada for almost 20 years.
