1. Master Chief: The highly trained Spartan-II supersoldier and protagonist of the Halo series, known for his resilience and duty to protect humanity.
2. The Arbiter: Once a Covenant fleet commander, Thel ‘Vadam became an Arbiter, fighting alongside humanity against the Flood and Covenant.
3. Sergeant Major Avery Johnson: A charismatic and battle-hardened UNSC Marine who played a key role in the Human-Covenant War.
4. Captain Jacob Keyes: A brilliant UNSC naval officer recognized for his innovative tactics and leadership during pivotal battles.
5. Fred-104: A member of Blue Team and Spartan-II supersoldier, known for his exceptional leadership and combat skills.
6. Edward Buck: Former ODST and later SPARTAN-IV, Buck is a determined soldier with extensive battlefield experience.
7. Noble Six: The silent yet pivotal Spartan-III in Halo: Reach, known for their sacrifice in the defense of Reach.
8. Atriox: The cunning leader of the Banished, a formidable force that poses a new threat in the Halo universe.
9. Spartan-B312: A mysterious Spartan-III who played a crucial role during the Fall of Reach, best known as Noble Six.
10. Cortana: An AI with unmatched intelligence, originally partnered with Master Chief, and later seeking to shape galactic peace.
1. Cortana: A pivotal AI character, initially aiding Master Chief and later pursuing her vision for peace and control in the Halo universe.
2. Dr. Catherine Halsey: The mastermind behind the SPARTAN-II program, whose work changed the course of human-Covenant relations.
3. Commander Miranda Keyes: A respected UNSC officer known for her strategic brilliance and sacrifice during the war.
4. Kelly-087: A Spartan-II famed for her speed and reflexes, making her one of the most agile combatants in the series.
5. Linda-058: An expert sniper and Spartan-II, renowned for her deadly precision in battle.
6. Catherine-B320 (Kat): The intelligent second-in-command of Noble Team, known for her planning and bravery.
7. Commander Sarah Palmer: Leader of Spartan forces on the UNSC Infinity, known for her direct combat skills and leadership.
8. The Librarian: A Forerunner figure instrumental in guiding humanity’s future, known for her wisdom and influence.
9. Tul ‘Juran: The first female Elite in the Swords of Sanghelios, an inspirational figure for gender equality among her people.
10. Veronica Dare: A determined ONI officer who played a critical role in key operations during the war against the Covenant.