Who voiced Cave Johnson in Portal 2?

Cave Johnson in Portal 2 was voiced by J.K. Simmons.

Johnson is the founder and chief executive of Aperture Science, the fictional research company behind the testing facility. Although players mostly encounter him through prerecorded announcements, Simmons gives the character a booming, eccentric performance that contrasts with the sterile voice of GLaDOS and the nervous chatter of Wheatley.

Cave Johnson does not normally appear as a living character during the game's present-day events. His recordings guide Chell through older, abandoned sections of the facility and reveal Aperture's history, including its increasingly dangerous experiments and Johnson's obsession with scientific competition.

A common mix-up is Stephen Merchant, who voices Wheatley, another major Portal 2 character. John Cleese voices a personality core in the game's cooperative-related content, but not Cave Johnson. Simmons later reprised the role in other Portal-related projects, including Aperture Desk Job.