A spokesperson for Mitte confirmed the death to Variety.
"It is with deep sadness that we announce the passing of beloved actor, philanthropist and dedicated advocate for the rights of people with disabilities, RJ Mitte," a statement said.
Like his character Walt Jr. in "Breaking Bad," Mitte lived with cerebral palsy and fought throughout his career for people with disabilities to be visible and represented in Hollywood.
"Drawing on his own experiences living with cerebral palsy, Mitte brought authenticity to the role and created a platform to increase awareness of disabilities and promote inclusion," the statement continued.
No cause of death has yet been announced.