What is Mike Dirnt's real last name?

Mike Dirnt’s real last name is Pritchard; his full birth name is Michael Ryan Pritchard.

Dirnt is the stage name of Green Day’s bassist, backing vocalist, and co-founder. He met Billie Joe Armstrong in the East Bay punk scene, and the pair became the core of the band that eventually developed from Sweet Children into Green Day.

The nickname “Dirnt” is commonly linked to the sound Pritchard made while pretending to play bass as a child. It became his public identity, so many listeners know him primarily by the stage name rather than by Pritchard.

He is sometimes mistakenly identified as “Mike Wright” or “Mike Armstrong” because of Green Day’s close-knit lineup. Those are not his surnames: Armstrong is Billie Joe’s last name, while Wright belongs to drummer Tré Cool’s birth name.