Ernesto Alvarez is a Latino C.O. who hates the inmates, believing them all to be scum. He is one of the guards that 'greets' Torque and escorts him to his cell, profusely expressing his distaste for the inmate along the way.

Ernesto is very proficient with Thompson sub-machine gun. Unlike most of C.O.s and inmates who died shortly after encountering malefactors, Ernesto managed to survive for several hours despite the non-stop assaults by Malefactors with only one thought in his mind: his family.

When the two meet up again, they form a shaky truce. Concerned with the fate of his wife and children, who are in town, he goes into town to look for them. He eventually comes to see Torque in a more redeeming light during their trek across the island, as several visions of Torque's family convince him that Torque may not have murdered them. His whereabouts and the fate of his children are both unknown.

His wife, Consuela, wrote the Island Location Archives, and she also calls the prison at one point by radio, trying to get in touch with Ernesto. She survives the island and makes it to Baltimore.

His voice is provided by Mark Dias.