As its first of two mandatory rookie runs in Friday first practice sessions, Mercedes has handed the 21-year-old Dane a run in the team's Mercedes W14 at the Mexico City race at the end of October.
"I'm incredibly proud to be doing the FP1 session in Mexico City with the team, it's a dream come true," Vesti reacted to the news.
"To think in less than two months that I'll be doing my first official Formula 1 session with Mercedes, who have won eight consecutive Constructors' Championships, is amazing.
"It's taken a lot of hard work, and this is a very important step for me on my journey."
Mercedes chief Toto Wolff added: "Fred has executed an impressive Formula 2 campaign so far this season.
"Driving in an FP1 session is the next step in his development and we're looking forward to giving him that opportunity.
"He is a talented young driver, not only quick but thoughtful, and he understands exactly what the team is looking for from him in the car."
It will be Vesti's second session in an F1 car, having also run for Mercedes in last year's Abu Dhabi young driver test.
Vesti also conducts simulator work for Mercedes back at its Brackley headquarters.
"Fred acquitted himself faultlessly in the young driver test last year, so we're looking forward to having him in the car once again," said Mercedes' trackside engineering director Andrew Shovlin.
"He's shown what he is capable of in F2 this year, combining strong pace with consistency.
"Fred has been part of the team for several years now and has been a key part of our simulator development and set-up programme. We're therefore looking forward to giving him his first running in an F1 session on a Grand Prix weekend."
Competing in F2 with Prema, Vesti heads into the summer break in second place after losing the championship lead to Theo Pourchaire in Spa.
He crashed on the way to the grid of Sunday's feature race, leaving him unable to take the start.
Vesti, who has so far taken four wins in 2023, now trails ART Grand Prix driver and Alfa Romeo reserve Pourchaire by 12 points in the standings.
