Mercedes-AMG F1 has confirmed Valterri Bottas will replace Nico Rosberg to partner Lewis Hamilton for the 2017 season.
The announcement follows the German, Rosberg's, shock retirement days after winning the 2016 world championship.
Bottas' appointment brings an end to weeks of rumours Hamilton would be paired from everyone from McLaren-Honda's Fernando Alonso to Ferrari’s Sebastian Vettel.
The Finnish driver, 27, currently races for Williams F1 team. During his five-year spell, Bottas has competed in 77 races securing nine podium places but no wins.
Speaking at the German race team's UK HQ in Brackely, Bottas said: "It's going to be mega to drive a Silver Arrow. I'm prepared to work as long as it takes to get everything out of the car. I'm still missing my first win so that's going to be my first mission".
Mercedes-AMG F1 used the new driver announcement to also confirm it would launch its new W08 Hybrid race car on February 23.
In a strange twist of fate Bottas' departure from Williams sees team mate Felipe Massa, who had retired after his 250th F1 race, recalled from his retirement.
Massa was brought back to head Williams' driver line-up i order to heal a rift with key sponsor Martini who demanded a senior, experienced driver to lead the team.
Massa, 35, who signed a one-year deal to return to F1 will race alongside 18-year old Canadian rookie, Lance Stroll.