In 2016, he became reserve driver, where he deputised for Fernando Alonso at the Bahrain Grand Prix, impressively scoring a point on his debut. He was promoted to race driver to partner Fernando from the start of the 2017 season, and has contested 34 grands prix with the team to date.
"We're immensely thankful for Stoffel's dedication, hard work and commitment during his time at McLaren," said Zak Brown. "He's a talented racing driver with an incredible list of accolades in his junior career. We're proud to have played a part in his break into Formula 1, from his role as test driver to his fantastic points-scoring debut in Bahrain in 2016.
"It's clear we haven't provided Stoffel with the tools to show his true talent, but throughout our relationship he's proved to be a fantastic team player. His work ethic is impressive, he has a great reputation within the team and we've really enjoyed working with him. Of course, we would have loved to achieve more success during our time together, but that doesn't detract from the fact that he will always be a part of the McLaren family of grand prix drivers.
"For now, we look to the future and to the remaining grands prix in 2018, where I know both Stoffel and Fernando will be pushing hard to fight for as many points as possible before we close the curtain on this season.
"We wish Stoffel all the best in whatever direction he chooses to take next in his career, and we'll be supporting him all the way. We will announce our full driver line-up for the 2019 season in due course."
"I'm very grateful to McLaren for investing their faith in me over the past five years," added Vandoorne. "I joined McLaren as a young driver and have since seen my career progress within the team from Test and Development Driver to Reserve Driver and then to full-time race driver.
"While we haven't achieved the success we'd all hoped for, I've really enjoyed the past two seasons racing for McLaren and I have a great relationship with everyone in the team.
"My time at McLaren has been a great chapter in my career and I'm thankful for the opportunity the team, Shaikh Mohammed bin Essa Al Khalifa and Mansour Ojjeh have given me to gain valuable Formula 1 experience and develop as a driver. I intend to give it my all for the remaining seven races of this season, and will announce my plans for next season in due course."