With Caterham having gone into administration last month, Ericsson has secured his own future with a move to Sauber for his second season in the sport.
Sauber, like Caterham, are without a point in this year's campaign and it remains to be seen who will complete their 2015 driver line-up, with Adrian Sutil and Esteban Gutierrez currently occupying the seats.
Speaking after Sauber's announcement on Saturday, Ericsson, 24, said: "Fresh from a very turbulent week, I was suddenly given my best early Christmas present ever.
"The Sauber F1 Team has put its trust in me for 2015, and it makes me proud, as Sauber is known to be one of the best teams in developing young drivers.
"It will be a great challenge. I will give my very best to develop both as a driver, and to be part of the challenge to put the Sauber F1 Team back closer to the front where it belongs."
Team principal Monisha Kaltenborn added: "We have got to know Marcus as a highly motivated driver. He did not have an easy rookie season this year in Formula One, however, he kept calm and improved continuously, mainly in the last races.
"We are convinced that signing Marcus can give the team a fresh impetus."
Ericsson's best finish came in Monaco in May when he took 11th spot, while five of his 16 races ended retirements.