Dr. Daniel Damian: This famed archaeologist from Kingston University was the first man of the 20th century to witness a Celestial Host. While his daughter Margo adventured with the Eternals in their clashes with the Deviants, he studied the City of the Space Gods, learning all about their ways from his good friend Ajak. Regrettably, following Margo's death, Dr. Damian went mad with grief, turned Ajak into a monster, and was seemingly slain by Ajak in a molecular explosion.

Margo Damian: It took Margo some time to find the courage she needed to face the kinds of challenges the Eternals faced every day, but ultimately, she braved an exploration of the City of the Space Gods, several encounters with the Deviants, a battle with a robot of the Hulk, a journey to New Lemuria, and an assault on a Deviant fleet! During this time, she fell in love with Ikaris. Margo was killed by Ghaur's scientists when they unsuccessfully tried to transform her into a Deviant. Ikaris buried her upon an island where many of his lovers over the centuries rest.

Dr. Samuel Holden: Poor Sam! As a colleague of Dr. Damian- and possibly somewhat close to his daughter Margo- he was asked to facilitate the introduction of the Eternals and Deviants to humanity! Unfortunately for him, neither side shared his anthropological enthusiasm. Sersi, on the other hand, found him irresistable. During his association with the Eternals, he has shared in the formation of a Uni-Mind, witnessed a battle with a robot of the Hulk, stood face-to-face with Priestlord Ghaur, and gradually, he overcame his initial meekness. He is also one of the few humans who remembers the details of the Fourth Host's visit to Earth. Why the Celestials chose to allow him to remember them has not been revealed.

Karkas: Though monstrous in appearance, and bred as a Mutate gladiator in Lemuria, Karkas is the gentlest Deviant of them all. His heart has always been in philosophy, not war, though he can be fierce when provoked. At his plea, Thena brought him and Ransak to Olympia, where Karkas was able to exercise his mind, and grow as an individual. But when Kro declared war on Ghaur, he chose to join the fight. Tragically, he was mutated by Apocalypse into a gigantic monster, which Ransak defeated. Whether or not Karkas survived his friend's attack, or will ever regain his true form, is unknown.

Ransak the Reject: Though this "Sweet Prince" may seem handsome in appearance, within, Ransak the Reject is a cauldron of rage. Due to his human-like appearance, he was raised a Reject in the Deviants' gladiator rings, never knowing the identity of his father- the geneticist Maelstrom. Warlord Kro recognized Ransak's genetic stability as a good sign for the Deviant people, and thanks to his pressure and that of Karkas, Thena brought Ransak to Olympia. At first, Ransak only traveled with Thena and Karkas, but he was later sent to be educated by the wise samurai Kingo Sunen in warfare and discipline. Recently, Ransak survived the destruction of Lemuria, and was forced to defeat Karkas in battle. He is currently a member of Ikaris' "New Breed" as "Warhead".

Thor: Thor first met the Eternals during the time of the 3rd Host, though he only regained his memories of their travels in recent times. When Thor learnt of the Celestials' attempt to judge Earth, he stood alongside the Eternals, incurring the wrath of the Forgotten One, avatar of the One Above All. Thor defeated the Forgotten One after a furious battle, but they developed a strong bond of comradeship. When the Eternals and Asgardians went to war with the Celestials, Thor joined them in the battle, and following the death of his father Odin, his rage caused more damage to the Celestials than all the Eternals combined! Since then, Thor has both opposed and aided the Celestials on other worlds, and aided the Eternals against the Dreaming Celestial. He has also served with Gilgamesh, Starfox and Sersi as members of the Avengers.

The Avengers: Earth's Mightiest Heroes have included Sersi, Gilgamesh and Starfox among their ranks, and they have aided the Eternals against attacks by Maelstrom, the Dreaming Celestial and Blastaar. Individual members, including Quasar, Captain America, the Black Knight and Thor, have developed strong friendships with some Eternals.

Dave Chatterton: Dave Chatterton just wanted to die when he leapt from a rooftop. Fortunately for him, he passed by Sersi's window. Unconvinced by his suicide motives, Sersi determined to teach Dave how to love life again. Dave became involved in several altercations involving the Eternals and Deviants, and gradually gained courage, and self-respect. When Sersi went to Lemuria, he followed her, and learnt she had been mind-controlled to kill Ikaris. Dave heroically took Ikaris' blast for him, and died a hero.

Yrdisis Though Yrdisis was a member of Kro's revolutionaries, she cared very little for their efforts. Full of rage, she cared only for her art. But after encountering the Eternal Khoryphos by chance, she realized the Eternals were not as she had been educated. In Khoryphos' musical efforst, she found both a kindred spirit and a lover. Together, they smuggled Deviants out of Lemuria and to safety, and aided the Eternals against Brother Visis.

The Fantastic Four: The first familly of the Marvel Universe became involved in the attack on on the Eternals' Deviant allies by agents of Maelstrom, and aided the Eternals in defeating Maelstrom.