Paris and Los Angeles had wanted to host the 2024 event, before LA agreed to wait an extra four years after the IOC made guarantees on funding.
The “tripartite agreement” between the International Olympic Committee (IOC), Paris 2024 and Los Angeles 2028 was ratified in the Peruvian capital Lima on Wednesday.
The compromise sees both cities join London as three-time hosts of the summer Games, with Paris getting its wish to go first and celebrate the 100th anniversary of its last Olympics in 1924.
Meanwhile LA, hosts in 1932 and 1984, gets the certainty of a Games without a bidding contest and early access to at least £1.8bn in shared revenue to kickstart its legacy plans 11 years early.
IOC president Thomas Bach told reporters: “Congratulations to Paris 2024 and Los Angeles 2028! This historic double allocation is a ‘win-win-win’ situation for the city of Paris, the city of Los Angeles and the IOC.
“It is hard to imagine something better. Ensuring the stability of the Olympic Games for the athletes of the world for the next 11 years is something extraordinary.
“These are two great cities from two great countries with a great Olympic history. Both cities are very enthusiastic about the Games and are promoting the Olympic spirit in a fantastic way.”
Paris and LA had been the only two candidates for the 2024 Games after Hamburg, Rome and Budapest withdrew from the race.