"I want to thank the people of my city --The Angelenos who have believe in Olympics. For the first in a generation, we are going to bring the Olympics home," Garcetti wrote.
Los Angeles has hosted the Summer Games for two times in history. The first was held in 1932 during the Great Depression. The 1984 Olympics in the second largest city was the first modern games that didn't leave behind large public debt.
United States Olympic Committee Chief Executive Officer Scott Blackmun issued a statement to welcome the decision as well.
"Today's decision by the IOC is historic and welcome. We look forward to working with our partners in LA, our friends in Paris, and the IOC administration to make the dream of bringing the Games back to the United States a reality," the statement said.
U.S. President Ronald Trump also tweeted Tuesday that he's "working hard" to bring the Summer Olympics to the city.
Garcetti said earlier that Trump promised to back the city's Olympic bid when the two spoke in last November following Trump's electoral college win.
NBC Los Angeles described the decision as a win-win result, emphasizing that the dual award could give the IOC a decade of stability with two world-class cities both have financially secure plan.
"The win-win option also guards against a 2024 loser refusing to bid again for 2028 and avoids inflicting a third recent defeat on Paris -- which lost with bids for the 2008 and 2012 Olympics -- and the United States. New York and Chicago both lost heavily for 2012 and 2016, respectively," NBS said.