Doohan, 21, will team up with Pierre Gasly as they look to compete further up the grid with a blend of experience and youth.
The young Australian will team up with the 28-year-old as he no doubt hopes to take the sport by storm during what will be his maiden season in F1.
Upon signing his new deal, Doohan said: "I am so happy to secure promotion into a full-time race seat in 2025 with BWT Alpine F1 Team.
"I am very grateful for the trust and belief by the team’s senior management. There is so much work ahead to be prepared and ready and I will give my best in the meantime to absorb as much information and knowledge to be ready for the step up.
"It’s exceptionally satisfying to be the first graduate of the Alpine Academy to be in a race seat with the team and I’m extremely thankful to those who supported me along the way to make this a reality. It's an exciting moment, a proud day for my family, and I look forward to taking it all in and pushing hard behind the scenes.”
Oliver Oakes, Alpine's new F1 team principal, added: "We are very excited to promote Jack into the race seat from next season and, in doing so, giving him the opportunity to showcase his skill and talent in Formula 1.
"Jack will become the first driver to graduate from the Alpine Academy into a race driver position with the team, so that is exceptionally pleasing for the team and its young driver pathway.
"Personally, I have worked with Jack back in 2019 and I am fully aware of his raw talent and potential. He is a very hard worker behind the scenes and his commitment is hugely valued by the entire team.
"Alongside Pierre, we have a well-balanced driver line-up with a good combination between youthful energy, experience, and pure speed. We look forward to working with both Jack and Pierre in order to keep developing the car and bring the team up the grid.”
Who is Jack Doohan?
Doohan, 21, is the current reserve driver for Alpine and has made his way up the ranks in motorsport, starting from a very young age.
After winning various karting titles in his youth, a move from Australia to Europe would eventually see him compete in Formula 4.
Doohan diligently worked his way through Formula 3 and Formula 2, before securing his current role as Alpine's third driver.
The youngster is now set to become the third Australian on the grid, alongside Daniel Ricciardo and Oscar Piastri.