What is the name of the actor who voices Groot in the MCU?

The actor who voices Groot in the MCU is Vin Diesel.

Groot first appears in Guardians of the Galaxy (2014) as Rocket’s tree-like companion and a member of the future Guardians team. Although Groot speaks almost exclusively through the phrase “I am Groot,” Diesel recorded many different deliveries so the line could convey distinct emotions and meanings. Diesel also provided Groot’s voice in several international versions of the film.

Groot’s on-screen performance involved more than voice acting. Krystian Godlewski portrayed an early motion-capture version, while Diesel and other performers helped shape the character’s physical movement. After the original Groot sacrifices himself during the battle with Ronan, a new Groot grows from a surviving branch. Baby Groot is therefore generally treated as a new individual rather than the exact same adult character with restored memories.

A common mix-up is Bradley Cooper, who voices Rocket, or Sean Gunn, who performs Rocket’s on-set movements and appears in other MCU roles. In later animated alternate realities, Groot has also been voiced by Fred Tatasciore, but Vin Diesel remains the canonical live-action MCU answer.