Cape Town - Lando Norris had admitted that being announced as a McLaren driver is a "dream come true", with the Brit in for the 2019 season.
The current F3 Champion, and F2 title challenger, will take over from Stoffel Vandoorne, who will leave McLaren at the end of the season.
The current Carlin racer has been part of the Young Driver Programme at the team since the early part of 2017.
He has taken part in several practice sessions for the Formula 1 team, whilst also taking part in F3 last year, and F2 this campaign.
"To be announced as a race driver for McLaren is a dream come true," Norris said in a statement.
"Although I’ve been part of the team for a while now, this is a special moment, one I could only hope would become reality."
"I’d like to thank the whole team for this amazing opportunity and for believing in me."
Having been with the team for the last 18 months, Norris has been able to hone his skills in the simulator, so he will not be a newbie come Australia in March.
"I’m also extremely grateful for the commitment McLaren has already shown in my development, allowing me to build my experience in a Formula 1 car in both testing and on Fridays during the past two race weekends."
However, there is still the small matter of the F2 Championship to win. Norris is currently 22 points behind fellow Brit, George Russell, with race weekends in Russia and Abu Dhabi left.
"For the remainder of 2018, my focus remains firmly on the Formula 2 championship," Norris added.
"My objective is to win the title before joining McLaren full-time, which will be tough, but I will fight as hard as I can for the remaining four races.
"I’ll also be working closely with McLaren at every opportunity to learn as much as possible from the drivers, engineers and mechanics to give myself the best preparation ahead of next year."
Norris will partner Carlos Sainz in 2019, with the Renault man making the switch to replace the outgoing Fernando Alonso for next yea