The British driver was widely expected to join the American-registered operation owing to its relationship with Ferrari.
Bearman is a Ferrari junior and has completed a number of Friday outings for Haas, most recently at the Spanish Grand Prix.
“It’s hard to put into words just how much this means to me,” said Bearman.
“To say out loud that I will be a Formula 1 driver for MoneyGram Haas F1 Team makes me so immensely proud.
“To be one of the very few people who get to do the thing what they dreamed of as a child is something truly incredible.
“To Gene [Haas], Ayao [Komatsu] and everyone at Haas, thank you for believing in me and for trusting me to represent your team.
“I’ve really enjoyed working with everyone since the first time we met in Mexico and I can’t wait to enjoy this moment with them and hopefully many more in the future.”
Haas is a customer of Ferrari, buying in both power units and other components allowed under the technical regulations.
It has a design office within the Italian marque’s Maranello campus overlooking the Fiorano test track.
As a Ferrari junior, Bearman has, in many respects, been an extension of that relationship.
“It’s an exciting thing to be able to give a young driver as talented as Oliver Bearman his first full-time seat in Formula 1,” said team principal Komatsu.
“He’s developed into an incredibly mature driver under the guidance of the Scuderia Ferrari Driver Academy and the world saw that for themselves when he was called in at the last minute to compete at the Saudi Arabian Grand Prix.
“Oliver proved he was more than ready for the task, and we’ve seen that for ourselves running him in the Haas cars in our FP1 sessions over the past two seasons.
“We’re looking forward to further developing him as a driver and reaping the benefits of his talent – both inside and outside of the car.
“Oliver’s a great guy and a very welcome addition to the team when he joins us for the FP1 weekends. Now we know that relationship is going to be longer-term, it’s a positive thing for all concerned.”
Bearman has one grand prix start to his name, having stepped in to replace Carlos Sainz at the Saudi Arabian Grand Prix earlier this season.
Having not participated in Friday practice, the Brit narrowly missed out on a Qualifying 3 berth before finishing eighth to score six points on debut.
His confirmation means all 10 teams now have at least one driver confirmed for 2025.
Nico Hulkenberg is set to leave the organisation for Sauber (Audi) at for next year while Kevin Magnussen’s future remains unclear.
Esteban Ocon has been heavily linked with a move to Haas to join Bearman after it was confirmed he would not renew his deal with Alpine.
Bearman currently competes for Prema in Formula 2, winning four times during his rookie season in 2023 with the Sprint win in Austria to his name this year.