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Mark O'Neil
Service Record

Ltcdr3 Lieutenant Commander (0-4)

Service Number



ODST Crest 105th Marine Expeditionary Force

Biographical Information


Date of Birth

November 4th, 2510

Physical Description



1.83 Meters (6'1" ft)


Dark Black



Miscellaneous Information

Human-Covenant War

"In peace, sons bury their fathers. But in war, fathers bury their sons. ."
―Mark O'Neil to Sergeant Darrel Mac during the Fall of Arcadia

Mark O'Neil (born November 4th, 2516) is a commissioned officer of the UNSC Navy, serving as a special warfare operator under the Office of Naval Intelligence's Special Operations Division. O'Neil served as an Orbital Drop Shock Trooper (ODST) specializing in covert and black operations until the death of his platoon during the Fall of Reach. After a brief attempt at retiring, O'Neil was thrown back into the conflict, ultimately serving during the war's most important conflicts such as the Invasion of Coral, Battle of New Mombasa, Siege of Voi, and Operation: BLINDFAITH.

Early Life

Mark Anthony O'Neil was born on a far off, long forgotten outer colony world during the early Insurrection. He lived a normal life for most of his childhood, living in lower middle class family and doing fairly well in school.

Military Career

O'Neil would graduate near the top of his class

Later Career

"Lieutenant Commander, Mark O'Neil, UNSC Navy. Graduated three years early from the Luna OCS at the top of his class. Fought during conflicts on Arcadia, Miridem, and ultimately Reach. Was leading a covert operations squadron during the planet's fall, witnessed the massacre of the entire group. He's since been a traumatized drunk, living on a backwater colony world. It's quite a shame to see such a decorated officer end up like this."
―Lieutenant Rose Zhenya, Office of Naval Intelligence

Invasion of Coral

Battle of New Mombasa