Mercedes development driver Esteban Ocon will replace Rio Haryanto at Manor for the remaining nine races of the season.
The highly rated Frenchman will make his Formula 1 debut at the Belgian Grand Prix (August 26-28) with the British outfit.
Ocon's arrival comes at the expense of former GP2 driver Haryanto after the Indonesian failed to secure the required funding to see out his maiden F1 season.
Haryanto had been backed by the Indonesian government but only had enough financial support to race in the opening 11 races.
Manor allowed Haryanto to compete in a further race beyond his initial commitment. He has since been offered a reserve driver role at the team.
His replacement Ocon, who has been racing in DTM this year, believes he is ready to make the step up.
“I'm thrilled that I'll be making my Grand Prix debut with Manor Racing later this month, and at Spa, of all circuits, which is the next best thing to my home race,” said Ocon, who won the 2015 GP3 title.
“I'm ready for this exciting step up, thanks to the experience I've gained as a Formula 1 Reserve Driver this season.
“I'd like to thank Renault Sport F1 Team and Mercedes-Benz for working together to make this happen, and to Manor Racing for the opportunity, which I'm going to grab with both hands.”
Manor boss Dave Ryan is confident Ocon has the skills required to help push the operation forward in the second half of the season.
“We are very pleased to welcome Esteban to Manor Racing for the remainder of the season,” said Ryan.
“Our team has made significant strides in 2016, including finishing in the points for the first time in Austria last month.
“We need to maintain our pace of development in order to achieve our ambitions, not only for this season but also for the longer-term, so the calibre of a replacement is key.
“We're confident that when Esteban makes his Grand Prix debut in Spa, we will have a very potent line-up with which to take the fight to our immediate competitors for the rest of the season.”