Colapinto, 19, made his debut in FIA Formula 3 last year with Van Amersfoort Racing, taking pole on debut in Bahrain before scoring sprint race victories at Imola and Monza. The Argentinian finished ninth in the drivers' standings with three further podiums to his name.
Williams announced on Monday that Colapinto had become the latest young driver to join its junior programme, as well as confirming he would remain in F3 with MP Motorsport.
According to Williams, Colapinto will be "immersed with the team both trackside and at the factory in Grove" as well as undertaking simulator work to assist his own development and that of the team's F1 car.
"It's a real honour to join Williams Racing Team as an Academy Driver," said Colapinto.
"They are one of the most successful teams in Formula 1 history and I am looking forward to following in the footsteps of my fellow countryman Carlos Reutemann.
"It's an incredible opportunity for which I am forever grateful. Thanks to everyone at Williams for putting their trust in me.
"I am also excited to announce that I will be back with MP Motorsport for the 2023 FIA F3 season. I really enjoyed my time with the team in Eurocup and FRECA and we achieved some great results together.
"The goal is to reach even higher this time. My first year in FIA F3 was all about learning and I will use all the knowledge I've gathered to aim for the title next year."
Colapinto joins a Williams young driver roster that includes three-time W Series champion Jamie Chadwick, Formula 2 driver Roy Nissany and Aston Martin Autosport BRDC Award winner Zak O'Sullivan, who will also be racing in F3 this year.
"We're delighted to welcome Franco to the Williams Racing Driver Academy," said Williams sporting director Sven Smeets.
"His career achievements since starting karting highlight Franco's natural ability behind the wheel and what he's capable of in the years to come. He had a standout rookie season in Formula 3 with several strong performances that led to podiums and wins.
"We look forward to working closely with Franco to support and nurture his development as a driver."