The 17-year-old was signed as Force India's development driver earlier this year, and will now take over behind the wheel of the VJM09 on both days of the test, which takes place on July 12-13.
Mazepin, currently competing in the FIA European Formula Three championship, has already attended several Grands Prix with the team this year, and has begun an extensive simulator programme to be ready for the occasion.
"I am extremely grateful for the opportunity to test the VJM09 at Silverstone," Mazepin said. "There’s no doubt it will be the biggest moment of my career and it’s something I’ve been working towards my whole life.
"It’s been a few months since I joined the team and I feel ready for this opportunity. I know it’s an important test for the team and they will be counting on me to do a good job, so I will work hard to make sure we achieve our objectives.”
Force India team principal Vijay Mallya said Mazepin's work behind the scenes had convinced the team of his qualities, adding: "In just a few months since his announcement as a development driver, Nikita has shown a great level of technical understanding to go with his driving skills.
"His progress in our simulator has been excellent and to be in the car during this test is the next step in his natural progression within the team. We are looking forward to working with him in Silverstone."
Mazepin will not be the only driver to make his F1 debut during the test, which is open to the public - Toro Rosso will hand a first call up to Brazilian Sergio Sette Camara.