In early 2017, Norris was signed as a junior driver with McLaren. Later that year, Norris tested for McLaren in a scheduled mid-season test. He set the second fastest lap in the second day of testing at the Hungaroring. In late 2017, Norris became the official McLaren test and reserve driver for the 2018 season. Norris participated in his first official practice session at the Belgian Grand Prix, recording 26 laps. Norris drove in six further practice sessions during the year.