Déjà: One of the lessons Déjà taught involved the famous Greek Battle of Thermopylae. Déjà took on the appearance of an ancient Greek goddess, and although which one is not specified, she seems to look like Athena, the goddess of wisdom and war.
Chiron: In the first Halo a multiplayer map is called Chiron TL-34. In Greek mythology, Chiron was a Centaur who trained many heroes including Achilles and Heracles.
Iris: In Greek mythology, Iris was a minor god of the Rainbow and the Messenger of the gods, like Hermes.
Operation: PROMETHEUS: This operation was named after Prometheus, a Titan who stole fire from god Zeus and gave it to mortals. He was subsequently punished by Zeus and his brother, Poseidon, the kings of Olympus by being forced to endure his liver being pecked out in the mornings by the vulture, Ethon, having it regrown, and then pecked out again the next day.
Also, 300 Spartan-IIIs fought in this battle and died; this is much like the Battle of Thermopylae, where 300 Spartan soldiers fought the Persians. At this battle, all of the Spartans died fighting but also put a heavy loss on the Persians losing many soldiers, paving way for a larger army to later finish the job.
Cyclops: This unit is named after the Cyclops, a kind of mythical giant with only one eye in the middle of their head. Some were descendants of the Titans, while another was the son of Poseidon. They were known to be skilled in forging weapons and the like. In the Halo Universe the Cyclops was an exoskeleton armor originally designed for construction.
UNSC Heracles: This warship was named after Heracles, a divine hero famous for doing the Labors of Heracles.
Melissa: Melissa is the name of one of the nymphs who helped save Zeus from his father, Cronus. She hid him in the hills and fed him milk from Amalthea and honey. When Cronus discovered this, he turned her into a worm. After Zeus came into power, he changed her into a queen bee, not being able to change her from an insect form.
Pallas Athena: Athena was the Greek goddess of Wisdom, Craft, and War; Pallas was her second name.
Gorgon: The deleted Halo Wars unit, the Gorgon, is a beast of Greek mythology. Gorgons were said to turn all those that looked at them into stone. In Halo Wars, they were originally intended to be an anti-air unit.
Tantalus: Tantalus was a system that was ordered that all ships aid Reach. Tantalus in Greek Mythology was punished in the Underworld to never be able to eat or drink anything.
Charybdis IX: Charybdis was the daughter of Poseidon. Originally a sea-nymph, she was turned into a sea monster by Zeus, after angering him by stealing Heracles' cattle. She also had a sister who wasn't a daughter of Poseidon.
UNSC Minotaur: A UNSC Prowler, this ship was probably named after the beast slain by Theseus.
The SPDR is repeatedly compared to the figure Arachne, due to the acronym's similarity with the word "spider".
51 Pegasi: Pegasi is the plural version of the flying Horse Pegasus and 51 Pegasi is part of the Pegasus constellation. In Greek mythology Pegasus was born from the blood of the gorgon Medusa after Perseus killed her. Later the Greek hero Bellerophon used Pegasus to help in his fight against the Chimera.
Leonidas: The third movement of the Delta Halo Suite from the Halo 2 Original Soundtrack. Leonidas was a Spartan king from around 488 B.C. to 480 B.C. He died during the Battle of Thermopylae, a battle earlier referenced in this article for it's significance in the Halo Universe.
Archimedes: Archimedes was an Ancient Greek philosopher, mathematician, and inventor, of whom discovered many modern units and techniques such as water displacement.
Hesiod: The name of this planet is likely a reference to the early Greek poet and rhapsode Hesiod, whose writings serve as a major source on Greek mythology, farming techniques, archaic Greek astronomy, and ancient time-keeping.
UNSC Herodotus: Herodotus was a major Greek historian that recorded the statistics and events of the Battle of Thermopylae.
SPARTAN Program: This program was named after the Spartan warriors who originated in Sparta in the southern part of ancient Greece. The city-state retained the superior military power in the region between 650 and 363 B.C. Its citizens were following the simplest way of life possible. They all exercised, and their children, like those used in the SPARTAN program, were trained from a very young age for many years.
Odyssey: The Odyssey is an ancient Greek novel written by Homer. It talks about the adventures of Odysseus since he left the Battle of Troy until he reached Ithaca, his homeland.
The story of the UNSC Spirit of Fire from Halo Wars can be compared to the story of Odysseus from Homer's The Odyssey. In the story, Odysseus and his crew fight at the battle of Troy and are taken to several different locations before their return home. While the Spirit of Fire has not yet returned to human-controlled space, they did fight during the five year long Harvest Campaign (Troy), and subsequently embark on a journey to several other locations, such as Arcadia and Shield 0459.
Kurt Ambrose: Kurt-051's surname, Ambrose, comes from the Greek word Ambrosia (Αμβροσία). Ambrosia is the drink the immortal Gods of ancient Greece enjoyed to drink, and the source of their power.
Ichor (used as a word for "blood" in Halo: The Flood): Ichor was the name for the golden blood of the gods at Olympus.
Origin of the Seasons: In the myth the Origins of the Seasons, when Persephone is able to leave the Underworld, Hades tricks her into eating 7 seeds from a fruit making the time to come back for 7 months.