- "Make the units better with new technology. Make more of them. And make them cheaper."
- —Colonel James Ackerson
The SPARTAN-III Program was an Office of Naval Intelligence, Section-III, Beta-5 Division program to produce cheap and expendable super soldiers to fight for the survival of Humanity and the UNSC colonies.
The SPARTAN-III Program was the successor and replacement to the Spartan-II Program. Engineered by Colonel Ackerson of the Office of Naval Intelligence, the SPARTAN-III soldiers (S-IIIs) were to be the next generation of super soldiers. Composed primarily of vengeful orphans from fallen colonies,  they would be cheaper to arm, train, and produce; chosen from a wider pool of candidates, and more numerous than their SPARTAN-II predecessors. They would rely on superior battle tactics, teamwork, and stealth rather than technology and equipment, to achieve their effectiveness.