Olympic gold medalist and America's Cup teammate Giles Scott will take over the driver's role, but Ainslie, 46, will remain as team chief executive.
Ainsley, the most successful Olympic sailor ever, insisted he would step away from his role as a driver to make way for the next generation.
Speaking about the decision, Ainslie – who won medals at five consecutive Olympics from 1996 onwards, including four golds – said: “This is probably the hardest decision I have ever had to make in my sporting career.
“Like any big decision, there are a lot of factors influencing it.
“As CEO of both Emirates GBR and the INEOS Britannia America's Cup Team, and more importantly a husband and father, you have to realize at some point that you can't do everything.
“It's gotten to the point where it's time to let the next generation come in and have their chance.
“We have a great talent in Giles Scott. He is one of the best in the sport and will suit this style of racing perfectly.
“He's an amazing sailor, one of the best sailors I've ever raced with, but he's also a very mature and balanced guy and that's why I think he'll do a great job at SailGP.
“I loved every minute I was in the league. We had some great moments and some tough moments, but I just loved it.
“It's the best sailing I've ever done in my career, it's so much fun. We have a great team at Emirates GBR that has a really exciting future, which I will be part of for many years to come.”
Scott admitted that he has some big shoes to fill, saying: “I still have some time to fill, but the Emirates GBR team is a fantastic team. All involved are very experienced, high-quality sailors.
“I have to step up and do the best job I can to fill those big old shoes that Ben left behind.”
Scott takes over as driver, alongside Hannah Mills OBE as strategist, Ian Jensen as wing trimmer, Luke Parkinson as flight controller, OBE Matt Gutrell, Neil Hunter and Nick Houghton as millers, and Hannah Diamond as reserve sailor.
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