 Meillard made his World Cup debut at age 18 in the Adelboden giant slalom in January 2015.At the Junior World Championships that March at Hafjell, Norway, he won a bronze medal in the Super-G, silver in the giant slalom, and gold in the combined.In February 2016, Meillard scored his first World Cup points at the Hinterstoder giant slalom, finishing in 27th place, and his first top ten (eighth) came the following week at Kranjska Gora.