In 2512, Hieronymus Stanforth became the head of Section Three. During his administration, Section Three was at its busiest. Project MJOLNIR, Project GUNGNIR, and the SPARTAN-II Program were all created during his tenure. He would then retire from this position to fulfill a more active frontline role in 2530.
Section Three's main responsibility is special projects for use within the UNSC. With that, it also oversees all of the various groups who do this. This has lead to the creation of many assets such as the NOVA project, the MJOLNIR Program, and many other "black ops."
Though a few of Section III's programs are well known and celebrated for their success, the Marines and top brass of the UNSC treat most with contempt. This is especially true of the Spartans, who are regarded as "freaks" by some Humans.
- ADM Danforth Whitcomb
- VADM Hieronymus Michael Stanforth
- CAPT Aaron G. Gibson
- LCDR Jilan al-Cygni
- MAJ John Smith
- Dr. Catherine Halsey
- Codename: SURGEON
- In the epilogue of Halo 3: ODST, the lighter carried by Avery Johnson bears an Orion logo, with Section Three's name on it, although this is difficult to see in-game.