Mark Ruffalo officially took over the role of Hulk in the MCU from Edward Norton starting with "The Avengers" in 2012. He has since continued Bruce Banner's story in "Thor: Ragnarok," "Avengers: Infinity War," "Avengers: Endgame," and the series "She-Hulk: Attorney at Law."
While a standalone Hulk film for Ruffalo has yet to materialize, recent rumors suggest his next appearance could be in "Spider-Man: Brand New Day."
Addressing these rumors during a red carpet interview for his new HBO series "Task," Ruffalo responded cautiously when asked about his involvement: "I don't know, I'm still waiting to hear, because I haven't seen the script yet." While not a direct confirmation, his understated response hints that an official announcement or surprise may still be on the horizon.
When pressed on what joining the new film would mean to him, Ruffalo laughed, stating, "If it were to happen, that would be pretty incredible. I grew up with these characters, and the Hulk has completely changed my life." He added that each collaboration brings new directors and fresh worldviews, allowing him to continuously experience the unique appeal of being part of the MCU. 
Fans have already begun speculating about Hulk's potential role in "Brand New Day." A popular theory suggests Bruce Banner could be a professor at Empire State University, while other rumors hint at events that might trigger Hulk's "rage mode" once again.
It's worth noting, however, that Ruffalo has not yet been confirmed for another major upcoming project, "Avengers: Doomsday."
"Spider-Man: Brand New Day" reportedly began filming in early August 2025 in the UK, with "Shang-Chi and the Legend of the Ten Rings" director Destin Daniel Cretton at the helm.