The 31-year-old forward joined LAFC from AS Saint-Etienne in 2022 and became a champion a few months later.
He is the top scorer in the young history of the California club, which launched in 2018, with 105 goals in 155 matches and was MLS's top scorer in the North American league in 2023.
Bouanga forms a feared attacking duo with South Korean Son Heung-min, who joined the black and gold of captain Hugo Lloris last year.
"At this club, performance matters," LAFC Co-President and General Manager John Thorrington said in a statement. "Denis has delivered at an elite level with historic consistency since the day he arrived, and he has helped us win multiple trophies.
"This new contract reflects that. We're proud of what he’s accomplished here and are motivated to continue building on that success together."
The 2026 campaign kicked off last weekend with LAFC dealing Lionel Messi's Inter Miami a 3-0 defeat.
Bouanga, signed as a Designated Player, is now set to play through this season and in a mini-season at the start of 2027, before a full campaign between the summer of 2027 and the spring of 2028 as MLS changes its calendar to align with the major European leagues.