The 2018 McLaren Autosport BRDC Award winner joins incumbents Rob Bell and Marvin Kirchhofer in McLaren's factory roster, with Joe Osborne and Euan Hankey understood to no longer be works contracted.
Gamble has raced in sportscars since 2019, most notably winning the European Le Mans Series LMP3 crown in 2020 with United Autosports.
The 21-year-old stepped up to the LMP2 class for 2021 and has won two ELMS races outright, while also building his GT experience with a full World Endurance Championship GTE Am programme aboard a Gulf Racing Porsche in 2021 and selected IMSA SportsCar Championship outings with the Heart of Racing Aston Martin squad.
He made his debut aboard a McLaren 720S GT3 in the Asian Le Mans Series at the Dubai Autodrome in February, where following a last-minute call-up by Garage 59 he claimed a fourth place finish alongside Benjamin Goethe and Alexander West.
A programme for Gamble, who claimed pole for his maiden British GT debut aboard a Century Motorsport BMW in 2019, has yet to be announced.
McLaren Automotive's director of motorsport Ian Morgan said: "Tom has proven to be a formidable sportscar and GT racer and will fit in well with Rob and Marvin in our factory driver line-up."
Meanwhile McLaren has named Goethe and Nicolai Kjærgaard as the first drivers signed to its new Junior Pro Driver category for promising young GT drivers.
Goethe was crowned champion in the Silver category of GT World Challenge Europe Endurance Cup last season driving a WRT Audi, and has been confirmed alongside Kjærgaard for this year's Sprint Cup campaign. The Danish duo meanwhile will race with Kirchhofer in the Endurance Cup.
Kjærgaard, the 2018 BRDC British Formula 3 runner-up, has been a regular with Garage 59-run Aston Martin and McLaren machinery in recent seasons.
Both will receive mentoring from the trio of factory drivers, in addition to newly-appointed McLaren Academy Driver Aston Millar.
Millar won the 2021 Ginetta Junior title and finished third in the final season of the GT Supercup last season.
"Benjamin, Nicolai and Aston are exciting future prospects and we are really looking forward to seeing how they progress through 2023,” Morgan added.
