Caroline, who beat Oscar Piastri and Logan Sargeant to win the 2017 British F4 title, made a successful switch to sportscars in 2020 by sweeping to the GT4 crown in a TF Sport Aston Martin alongside Dan Vaughan.
He switched last year to the GT4 European series in a Mercedes, but returned to the British championship to partner Ferguson for the final two rounds aboard the Speedworks Toyota Supra in GT4 and led impressively in the wet at Oulton Park.
The 23-year-old will now continue his partnership with Ferguson, who was frequently plagued by bad luck in his first season of British GT last season, but scored two third places at Silverstone and Snetterton alongside Scott McKenna.
Caroline, who have the opportunity to benchmark himself against factory driver Jules Gounon in the sister RAM entry, said 2022 will be "the most important year of my career yet".
"I’m so excited for this chance," said Caroline.
"I’ve been trying to get into GT3 for the last few years and I’m ready to grab this chance with both hands.
"I know that to achieve what I want to, which is to become a factory driver, I need to show what I can do at the highest level, and I know I’ve got the right team and the right car to do that this year."
Caroline added that he's targeting a championship challenge in his first season aboard the RAM Mercedes-AMG GT3, which Gounon's team-mate Ian Loggie and Yelmer Buurman have taken to two Pro-Am titles in the past two seasons.
He said: "British GT is an incredibly tough championship and I’ll be up against some of the best GT3 drivers around – you only have to look at Jules Gounon on the other side of the garage to know that! But I’m raring to go.
"I believe I’m at a point in my career where I have to go into each year with my eyes on the title. And even with the step up from GT4 it will be no different this year in GT3 – you have to aim high!
"I’ve tested a couple of GT3 cars before and, given my two years in GT4, I believe I’ve understood the fundamentals of GT racing now and I feel I’m ready for the step up to GT3.
"I liken it to my move from F4 to F3, the cars are a bit more powerful, lighter and have more aero.
"We’ll have some good pre-season running to get up to speed and I work so well with John. Even though we only had a few rounds together in GT4 last year we clicked from the start, and it’ll be great fighting at the sharp end with him in a RAM Mercedes-AMG.”
Ferguson said: "I will always have a driver alongside me that I really believe in, and I certainly have that with Jamie.
"He’s got so much raw talent and is a great lad to work with. I reckon he’ll be the surprise package in GT3 this year.”
RAM boss Dan Shufflebottom has lauded the Caroline-Ferguson axis as "a real future-proof pairing".
"John brings lots of racing experience and the GT4 points table would have looked a lot different last year without the bad luck he had," he said.
"Jamie is a star of the future, no doubt. His record so far is incredible and it’s easy to forget he’s only been racing for a relatively short time.
"I have no doubts that both will adapt really well to the Mercedes-AMG GT3, and I look forward to seeing how they progress across the season.”
