Romain Grosjean and Kevin Magnussen will both leave Haas at the end of the Formula 1 2020 season.
Grosjean joined the American-owned team ahead of their inaugural season in 2016, while Magnussen arrived the following year, but neither had been expected to stay for next year with Haas eager to make a fresh start.
Mick Schumacher and Nico Hulkenberg are among many drivers who have been linked with Haas seats, which are now both available for 2021.
"The last chapter is closed, and the book is finished," said Grosjean.
"I've been with Haas F1 Team since day one."
"Five years during which we went through highs and lows, scored 110 points in 92 races, but the journey was worth it. I've learned a lot, improved to be a better driver as well as a better man.
"I hope I've also helped people in the team to improve themselves. This is probably my biggest pride, more than any of the crazy first races in 2016 or the P4 at the Austrian GP 2018. I wish the team all the best for the future."