Alpine will run Mercedes engines from the 2026 season, the Formula 1 team confirmed on Tuesday.
The new deal has been widely expected since Alpine, Renault's F1 team, announced the end of its own engine programme in France.
Alpine's Mercedes deal, which also includes a gearbox supply, will start in time for the new set of F1 rules in 2026 and run until 2030.
Earlier this year Alpine bought back former Renault team boss Flavio Briatore to help facilitate a new engine supply deal.
Renault has insisted there are no plans to sell the team outright.
Alpine scored an unexpected double podium in Brazil, an anomoly in what has been a difficult season on and off track.
New team boss Oliver Oakes said earlier this year the Alpine team will need several years to be contending for podiums on merit.