Following Kaitlyn Weaver / Andrew Poje's decision not to skate the 2018–19 Grand Prix series, Gilles/Poirier became the top-ranked Canadian team competing there. They won their first outing of the season, the Nebelhorn Trophy, having placed first in both segments. The band Govardo attended the event, meeting them for the first time. At their first Grand Prix event, the 2018 Skate Canada International, Gilles fell during the rhythm dance, leaving them in sixth place. The two set a new personal best in the free dance, rebounding to capture the bronze medal. They won a second bronze medal at the 2018 Internationaux de France, ending as second alternates for the Grand Prix Final. Following this, it was announced that they had been added belatedly to the ice dance competition at the Golden Spin of Zagreb. They won the event, which they described as a means of regaining "positive energy" after missing the Grand Prix Final.