The Finn has impressed since making the switch from Williams to the Silver Arrows at the end of 2017 to replace Nico Rosberg and currently sits in third place in the World Championship standings after 13 races.
The 28-year-old recorded the first two wins of his F1 career this year, claiming the chequered flag in Russia and Austria, while he also has a further seven podium finishes to his name.
Team-mate Lewis Hamilton has recently called for Bottas to be handed a contract extension, having joined on an initial one-year deal, with the dynamic between the pair said to be a significant improvement on the relationship the Brit had with Rosberg.
Mercedes have now confirmed Bottas will drive for them again next year, much to the delight of the former Williams man who feels he has "earned the trust" of the team with his impressive performances.
“When the team hired me for the 2017 season, they took a leap of faith by putting their trust in my skills," he told the Mercedes F1 website. "This new contract for 2018 shows that I’ve earned that trust.
"I’m happy to have celebrated my first race wins in a Silver Arrow. However, there’s always room for improvement and I still have not shown my full potential.
"I will continue to work hard on and off the track, to further improve my driving, get even better results and show that putting their trust in me was the right decision."