Lando Norris and Carlos Sainz will continue with McLaren for a second season in 2020.
The team have taken up an option on the contract of Norris, 19, ahead of this weekend's British Grand Prix.
British driver Norris, who has impressed in his debut season, said: "It has been pretty awesome. It has gone better than I expected."
McLaren boss Andreas Seidl confirmed Sainz will also stay, saying: "They are the future for this team."
McLaren Racing chief executive officer Zak Brown said keeping the same driver line-up was "never in doubt" and that the team wanted to make it clear neither was available to move elsewhere as the driver-market "silly season" kicks into gear.
"It was always the plan," Brown said, "but a lot of teams were sniffing around, a lot of teams are unhappy with both their drivers and given how Carlos and Lando were doing it was in our best interest to eliminate any speculation."
Seidl added: "They both have multi-year deals with us. Lando of course being the rookie we had to make it probation time, which he successfully managed in the first part of the season. And in order to have full clarity with the outside world we wanted to confirm the driver line-up."
Norris surprising himself
Norris entered F1 this season with high expectations upon him after impressive results in junior categories but he has excelled with some strong performances, including two sixth-place finishes in Bahrain and Austria. He has qualified in the top six for the last three races and in the top 10 six times in nine races.
"I didn't expect anything going into F1," Norris said. "I didn't want to set targets or positions or anything. I just wanted to see how it goes and see what I can do. But I definitely didn't expect to be qualifying P6, P5 sometimes, finishing P6."
Seidl said: "What he has shown from the first race onwards in qualifying and the races plus all the work he is doing outside the car is impressive for an F1 rookie and it was quite a straightforward decision.
"We want to develop together. They are two top drivers in the future and hopefully we can make the same progress on the team side giving them the right machine to execute out there on the race track."
Strong progress for McLaren
McLaren ended last season sixth of 10 teams in the constructors' championship, and had the second-slowest car for much of the season, but they have made a dramatic step forward this year and lie fourth in the constructors' championship, 20 points ahead of closest pursuer Renault, as the season nears its halfway point.
Sainz, who will be going into his sixth F1 season in 2020, said he had been surprised by how quickly McLaren had moved forward.
"I always believed McLaren wouldn't be as far back as they were in 2018," he said. "I always believed that the lack of development they had in 2018 was to try and learn and put a better package for 2019.
"And the moment I spoke to the team back in August/September, I understood they more or less knew why they were going through such a struggle so the confidence was high that we weren't going to have such a bad year as 2018.
"What has pleasantly surprised me is that we have actually moved forward quite quickly from being in the middle of the midfield to suddenly having the last two weekends a very nice car to fight at the top of the midfield."
He said this was down to "hard work and dedication and understanding our weaknesses as a team, an organisation and of the car".
Sainz believes over the next few seasons McLaren can close in on Mercedes, Ferrari and Red Bull.
"I definitely feel we can reduce the gap," he said. "Can we win a title any time soon? Time will tell because there are going to be a lot of changes in F1 and it will be about which team adapts better. But I do believe McLaren are putting in the right steps to at least give it a good go."