You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
The 26-year-old has long been linked to a seat with the four-car team having stood-out as a co-driver in the Pirtek Endurance Cup rounds the past two seasons with the organisation.
He becomes the fifth Kiwi to earn a fulltime drive on the grid next year joining Scott McLaughlin, Fabian Coulthard, Shane van Gisbergen and Andre Heimgartner.
"Obviously it's good to have everything ready," said Stanaway, who will pilot the No. 56 Ford Falcon FG X. "It's been coming along for a while, but it's good to finally have the deal done. It's been a childhood dream for me to race in Supercars, so it's great to check that off the bucket list."
Stanaway drove superbly in tricky conditions in his category debut at Sandown in 2016 before breaking through to earn his maiden series win alongside championship regular Cam Waters at this year's Sandown 500.
Many experts have tipped him to be a genuine force in the seasons ahead but Stanaway is being realistic with his goals.
"The first objective is always just to get into the series," he said. "But there's a big difference between participating in the sport and being successful. I'm aware that I've got a long road ahead of me and a lot to learn, but I'm really motivated.
"I'm putting my best foot forward, and want to learn as much as I possibly can in my rookie season. I'm expecting it to be tough, that's just a realistic approach."
He joins 2015 series champion Mark Winterbottom, Bathurst winner Chaz Mostert and Waters in a strong four-car squad at Prodrive.
Team principal Tim Edwards is delighted to have secured the services of a driver that boasts race victories in the World Endurance Championship, Formula 2, and GP3 as well as his Sandown 500 win.
"We're obviously delighted to have Richie aboard with us full time, said Edwards. "For as young as he is, he brings more experience and achievements to the table than a lot of veterans, and he's impressed us every time we've put him on track.
"He's proven he deserves a top quality ride in this sport, and I'm glad he'll be racing for us rather than against us.
"Having Richie join the team really completes the package for us," added Edwards. "We'll head into 2018 with four great drivers in four fast cars, and we believe we'll be a threat to win any time out. We've elevated our expectations for next season, and we can't wait to hit the track."
Stanaway's first scheduled appearance with the four-car outfit will take place February 16 at Sydney Motorsport Park at a Supercars sanctioned open test. The Kiwi's first race event will be March 1-4 at the Adelaide 500.