Avallon-born Mbeumo previously represented France at U-21 level, making six appearances for Les Bleuets after progressing through the country's youth ranks.
However, the 22-year-old will now represent Cameroon - the land of his father - after being announced by the Cameroon Football Association on Friday.
"The federation have the pleasure to announce that the footballer Bryan Mbeumo has decided to play for the national football team of Cameroon - the Indomitable Lions," read the Federation's statement, signed by General Secretary Blaise Djounang.
"This decision, which is the culmination of conversations nourished with the president of FECAFOOT [Samuel Eto'o], is driven by the rediscovered credibility of FECAFOOT and the professionalism of the management of national team selections in Cameroon."
Mbeumo made his name with Ligue 1 side Troyes after coming through the club's academy, making his senior debut for ESTAC in February 2018.
After enduring relegation with Troyes later that year, he remained at the club during their failed attempt to return to the top flight the year after, before being signed by Championship club Brentford for a then-club record £5.8 million.
After a failed promotion attempt in the 2020 playoffs, Mbeumo excelled as the Bees finally reached the top flight in 2021 and adapted readily to life in the Premier League last season.
He had a hand in 11 goals (four goals, seven assists) as Thomas Frank's side finished 13th in the top flight, earning effusive praise from his coach during the course of the campaign.
"He's done very well for us so far this season," Frank told journalists in January, "He's been brilliant for us this year in the Premier League."
Mbeumo will now be hoping to be part of Cameroon's 26-man World Cup squad, to be submitted by head coach Rigobert Song before October 20.
The Indomitable Lions are set to compete in their eighth World Cup - an African record - and begin their campaign against Switzerland in Al Wakrah on November 24. They will then have to face Serbia and Brazil as they look to escape Group G and reach the knockouts for the first time since 1990.
Africa's five qualifiers for Qatar have been proactive recruiting uncapped and dual-national players ahead of the tournament, with Ghana confirming that Inaki Williams and Tariq Lamptey have committed their international futures to the Black Stars.