The 17-year-old has been part of McLaren's Young Driver programme since the start of the year and is expected to compete in Formula Two in 2018 after winning the European Formula Three championship this year.
"Lando is an outstanding young talent. Today's announcement is thoroughly deserved, and underlines the incredible high regard in which we hold his abilities," said McLaren executive director Zak Brown in a statement.
"His summer test for McLaren was also remarkably impressive, and was further proof that he is ready to step up and take on a role of this size, scope and responsibility.
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"At McLaren, we are all extremely keen to help him achieve his goal of racing in Formula One."
Norris, who will be 18 next week, will attend grands prix and have an active role in testing and the simulator, starting with a tyre test at Interlagos after next weekend's Brazilian Grand Prix.
He will stand in for race drivers Fernando Alonso, a double world champion, and Belgian Stoffel Vandoorne if either are unable to compete.
"I'm still working hard to finalise my own racing programme for 2018 -- we're close on a number of different fronts, but not quite there yet. I hope to be able to announce something shortly," said Norris.
(Reporting by Alan Baldwin, editing by Christian Radnedge)
