Manor have announced that Esteban Ocon will replace Rio Haryanto for the remainder of the season.
Ocon, the 19-year-old Frenchman, will team up with Pascal Wehrlein starting from the Belgian Grand Prix at the end of this month.
Mercedes junior Ocon had spent the first part of the season on loan to Renault as their reserve driver.
But he will now be handed his full Formula One debut after Haryanto, heavily sponsored by Indonesia's state-owned oil company Pertamina, ran out of money to fund his seat.
"I'm thrilled that I'll be making my grand prix debut with Manor Racing later this month," Ocon said. "I'm ready for this exciting step up, thanks to the experience I've gained as a Formula One reserve driver this season.
"I've visited the Manor Technical Centre already, for my seat fit and to meet with the wider team, so we'll be ready to hit the ground running after the summer break.
"They've done a great job this season and I'm excited that I've been tasked with helping them to build on that progress. I can't wait to get started."
Both Ocon and Germany's Wehrlein are members of Mercedes' young driver programme.
Toto Wolff, the Mercedes boss, added: "We are very pleased that this opportunity has opened up for Esteban, and that Manor has again had the confidence to give a chance to a promising young talent.
"Manor is just the right environment for a young driver to get his first experience of F1 - a professional, small team that is on a positive upward trend and where the driver can make a real difference."
Meanwhile, Haryanto, who out-qualified Wehrlein in four of his 12 grands prix, has been offered a reserve role at Manor for the rest of the campaign.
Manor boss Dave Ryan added: "Rio has been a much-valued member of our team since January, when we signed a contract with him for this season.
"Some time ago, his management indicated that they were experiencing difficulties honouring the obligations of that contract beyond the Hungarian Grand Prix.
"Rio's team have worked tirelessly to try to resolve that situation with his Indonesian backers and we have supported those efforts as much as possible, including allowing Rio to race in Germany.
"Unfortunately we reached a point where, in the best interests of the team, we were forced to explore other options for the remainder of the season."
Source: PA
