The Chief Science Officer, or C.S.O., was a position aboard the USG Ishimura. The C.S.O. had the responsibility of overseeing the science wings and had authority on the Medical Deck. He would enforce protocols and, in times of emergency, could enact quarantine procedures. The C.S.O. was trained to both act as a scientist and doctor and any protocol or quarantine enacted by the Officer could only be vetoed or overruled by the Ship's Captain. The last known C.S.O. of the Ishimura was Terrence Kyne, who attempted to stop the Necromorph Infection from occurring but was stopped by Captain Matthius. He later came to formulate and help execute the plan to have Isaac Clarke return the Red Marker to Aegis 7.
- The position is likely the counterpart to the Senior Medical Officer (S.M.O.) which was held by Nicole Brennan.