Britain's Jordan King is to drive for Manor in the first practice session at the United States Grand Prix on Friday.
The 22-year-old, who competes in the GP2 series, tested for Manor at Silverstone and Barcelona this year but has never driven an F1 car during a grand prix weekend.
King is fifth in the GP2 drivers' standings with one round remaining in Abu Dhabi next month.
He will take over Pascal Wehrlein's car for the session at Austin.
"You dream of driving an F1 car from a young age and then to be a part of a race weekend and be on the circuit with everyone else is something very special," King said.
German Wehrlein scored Manor's only championship point this season when he finished 10th at the Austrian Grand Prix in July.
Subscribe to the BBC Sport newsletter to get our pick of news, features and video sent to your inbox.