The actor, best known for his role as Walter White Jr in the beloved TV show, took his own life on Monday in Texas.
Mitte, who was diagnosed with cerebral palsy aged three, became a successful actor thanks to his role in the show, alongside Bryan Cranston and Aaron Paul.
He also advocated for other actors in Hollywood with disabilities.
Confirming his death, Mitte's representative said in a statement: "It is with profound sadness we share the tragic passing of beloved actor, philanthropist, and passionate disability rights advocate RJ Mitte.
"RJ Mitte was best known for his role as Walter 'Flynn' White Jr. on AMC's critically acclaimed, award-winning series Breaking Bad.
"Drawing from his own experience living with cerebral palsy, Mitte brought authenticity to the role and built a platform on disability awareness and inclusion.
"Beyond entertaining friends and family around the world, he served as an ambassador for United Cerebral Palsy and Shriners Children's."
News of Mitte's death comes just a year after he announced his engagement to Kennedy Suarez, after proposing on her 30th birthday.
He told People at the time: "I'm thrilled to have found my person, my partner in life who makes me want to be better, no matter what we're doing.
'Kennedy is my everything and I can't wait to officially start our life together and see what adventures life takes us on next."
Following the proposal, Suarez took to Instagram to share her excitement, writing: "My 30th felt like a fairytale…. I have the man of my dreams by my side we are doing what we love most — helping others."
Mitte is survived by his parents, and younger sister Lacianne.
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