Coached by his father, McDavid won four Ontario Minor Hockey Association championships with the York Simcoe Express, but he left the team in 2011 to join the Toronto Marlboros of the Greater Toronto Hockey League (GTHL). There, McDavid was named the GTHL Player of the Year and the winner of the Tim Adams Memorial Trophy. He was granted exceptional player status in 2012 by Hockey Canada, which allowed him to begin playing junior ice hockey at the age of 15. The Erie Otters of the Ontario Hockey League (OHL) selected him first overall in that year's draft, and he played there until 2015. McDavid's OHL career concluded with a 2014–15 season in which he recorded 120 points and received a number of OHL and Canadian Hockey League (CHL) awards, including the Red Tilson Trophy, Wayne Gretzky 99 Award, and CHL Player of the Year awards. McDavid also represented Canada at several international competitions during this time, winning gold medals at the 2013 World U18 Championships and 2015 World Junior Championships.
After finishing his junior hockey career, McDavid joined the Oilers for their 2015–16 season. Despite missing three months of his rookie season due to a fractured clavicle, he was named to the NHL All-Rookie Team and was a finalist for the Calder Memorial Trophy. The following year, the Oilers appointed 19-year-old McDavid the youngest captain in NHL history. Recording 100 points during the 2016–17 season, at the age of 20, McDavid became the second youngest player to win the Art Ross Trophy for the leading scorer in the NHL. He was also awarded the Hart Memorial Trophy, Ted Lindsay Award, and was selected to the NHL First All-Star Team. Although the Oilers missed the Stanley Cup playoffs during the next two seasons, McDavid scored 41 goals in consecutive years. He injured his knee in the final game of the 2018–19 season but underwent a nonsurgical rehabilitation process that allowed him to return in time for the start of the 2019–20 season. In 2020–21, despite the COVID-19 pandemic shortening the NHL season to only 56 games, McDavid recorded 100 points for the fourth time in his career. In 2023–24, McDavid captained the Oilers to the Stanley Cup Final, their first since 2006. McDavid won the Conn Smythe Trophy as the most valuable player in the 2024 Stanley Cup playoffs, becoming only the sixth player, second skater, and first since Jean-Sébastien Giguère in 2003, to win the award despite not winning the Stanley Cup.