It was announced on Wednesday at the livery launch of the A424 Hypercar that the #35 machine will be crewed by Paul-Loup Chatin, Charles Milesi and Ferdinand Habsburg, with the #36 driven by Nicolas Lapierre, Matthieu Vaxiviere and sportscar rookie Mick Schumacher.
Gounon was also revealed as the reserve driver for the Signatech-run team that most recently competed in the Hypercar division in 2022 with the grandfathered A480 LMP1 car previously known as the Rebellion R13.
Reigning Intercontinental GT Challenge champion Gounon described his first test of the car in Barcelona as "magical".
"I was really looking forward to getting to know the Alpine A424, and I would like to thank Mercedes-AMG for allowing me to join Alpine in this role," he said.
"Many of the GT greats I've battled against over the years are now with various constructors in Hypercars, and this was a personal dream of mine.
"I remember my father [Jean-Marc], who raced in LMP1 in 2005, and I promised myself then that I would do everything I could to win the 24 Hours of Le Mans overall in a prototype.
"That's not yet the case as I'm a reserve driver, but I hope to work well and continue to improve to get closer to that goal in the future."
The car developed with ORECA will debut in the WEC season opener, the Qatar 1812 km, on 2 March.
Team principal Phillipe Sinault said he was convinced the V6-powered machine has "got enormous potential" and expressed confidence in its driving crews to perform.
"Our driver line-ups perfectly reflect our desire for alchemy and our consideration of the human being as one of the essential elements and one of the keys to the project's success," he said.
"We haven't made any compromises, and our first draft of the line-up has now come to fruition. Speaking with Bruno Famin on the subject was a pleasure as we agreed immediately.
"They're all tremendously high-quality drivers with experience and high levels of commitment and expectations.
"I think we've made the right choices, and I have confidence in this team, which for us is ideal to write this new chapter for Alpine in Hypercar."