Led by Lando Norris and Oscar Piastri, McLaren accumulated 666 points to finish 14 clear of Ferrari and last year's defending champions Red Bull a long way back in third spot.
The British outfit aim to consolidate their position as the top team in F1 next season, but must do so without the talents of one of their most influential figures.
Stella hails Imai influence
Hiroshi Imai first joined the squad in 2009, before being promoted to the role of chief race engineer in 2017 and director of race engineering in 2021, but is now set to move on to a fresh challenge.
It is believed he will seek opportunities in his native Japan rather than make the switch to a rival F1 team
In a statement published on PlanetF1.com, team principal Andrea Stella hailed Imai's impact.
He said: “Hiroshi has been at McLaren for a long time. He has been a fundamental contributor to what the team have achieved over the years.
"A person of great integrity, a person of calmness. Everyone appreciates his calmness, his great organisation.
“But at the same time it’s always been a point of reference for everyone in the team who needed some advice, who needed to have a wise opinion, and they have always known that could find it in Hiroshi.
“There’s one aspect of Hiroshi we all love, [it’s] that when it was the time to go racing, the Samurai inside Hiroshi would come out and he would become one of the tougher racers, but always incredibly respectful and with great style.
“We are all very thankful and grateful to Hiroshi for what he has given to McLaren.
“He will always be part of the family and I’m delighted that he has achieved the World Championship in his final year at McLaren, because he will always say that he has been World Champion for the rest of his of his life.
“We wish Hiroshi all the best, and I’m sure we will have more opportunities to see him around in the future.”