The main player character in the numbered Halo games. Officially known as Master Chief Petty Officer John-117, or simply "Master Chief", he is a supersoldier created by the United Nations Space Command known as a SPARTAN, tasked with performing operations that would be exceedingly difficult for unaugmented humans. His most famous exploits came during the Human-Covenant War, in which he destroyed one of the titular Halo rings, assassinated one of the Covenant's leaders, and played a key role in stopping the parasite known as the Flood for good, among other heroic acts.
John is one of the most iconic video game characters in the Western world, with his distinctive appearance and gravelly voice, provided by Steven Downes.