Sergeant John Carver is the secondary main character and protagonist to Isaac Clarke. He is an Earthgov soldier who appears in the Dead Space series for the first time in Dead Space 3. Carver was recruited by Captain Norton when his home planet Uxor was infested by Necromorphs after Jacob Danik released the Marker there. Carver lost his wife Damara and son Dylan in the incident and joins Ellie's Marker team along with Norton to stop the Markers once and for all. When Ellie traces the Marker signal back to Tau Volantis, he and Norton are sent to recruit Isaac for the mission. His role is to help lead character Isaac Clarke find a Unitologist Marker on the ice planet Tau Volantis, although he remains suspicious of the Clarke's true motivations. This is due to what Carver perceives as an obsession that Clarke has with Ellie, his old partner in arms against the Necromorphs from Dead Space 2. Carver has doubts as to whether Clarke will act reasonably when Ellie's life is on the line, and she's gone missing in the icy wilds of Tau Volantus.

During the events of the game, Carver is responsible for protecting the group, namely Isaac. While reaching closer to the Markers, Carver isn't totally sound himself and begins to have hallucinations of his son and wife that are both part of his guilt and the Markers. Like Isaac's ordeals with the hallucinations of Nicole Brennan, he must overcome them and realize that it was not his fault, and whatever he is seeing is not there.