Delta Squad was a elite military unit of Spartan-II Commandos in the UNSC Special Forces and now a unit of Great Frontier Red Team. A unit of nigh-total independence from the common command, Delta Squad is a special force unit that soley performs their missions either on the frontlines or undercover work such as espionage and sabotage. One of the most well known units in the UNSC, Delta became infamous their skill and resourcfulness on many planets throughout the galaxy and during the war. Delta Squad was chosen by Malcolm Hargrove to be sent to Project Freelancer under the guise of stopping insurrectionsts that had developed similar power armour, and to train the Red soldiers. Delta's true re-location information revealed they were sent there to act as subjects of experimentation of testing the prowess of Freelancer agents.
In the Great Frontier Red Team, Delta Squad soon developed a sub-unit in the team, becoming a elite unit that became known as Delta company.