Apollo is a superhero who first appeared in the Stormwatch series, but is best known for his role in The Authority. While visually distinct, Apollo is cast in the mould of the Superman archetype.

Apollo is notable for being among the first openly gay superheroes in print, although several years behind Marvel Comics' Northstar. He married fellow Authority member Midnighter and both adopted Jenny Quantum.

Warren Ellis introduced the character shortly after taking over writing duties on the Stormwatch title, when he had Apollo and Midnighter encounter the then-active Stormwatch team. The story was set in 1998, immediately after Bendix's fall, when Christine Trelane had cracked Bendix's old files and discovered evidence that two rogue former Bendix agents remained alive. In flashbacks, Apollo was introduced as a member of a "black ops" Stormwatch team so secret that no one but the first Weatherman, Henry Bendix, knew of its existence. Apollo's solar-powered abilities—including super-strength, heat vision, and a high degree of invulnerability—were presented as the consequence of Bendix's bioengineering.

The first story arc (collected in the Stormwatch trade paperback A Finer World) described how, of the seven-member team, only Apollo and Midnighter survived, going rogue after their first Stormwatch Black mission and spending five years undercover fighting for a finer world in the alleyways of America. Jackson King intercepted them on a mission to seize weapons made in the "Nevada Garden", a leftover of the first Engineer. He ordered Fahrenheit and Hellstrike to tag them with fetishes so they could be transported into SkyWatch. At first Apollo and Midnighter attacked the Stormwatch team, believing them under Bendix's orders. However, they ceased the attack once they were told Bendix was dead. With King's help, they destroyed the Nevada Garden, and Trelane gave them new lives away from Stormwatch.

In 1999, when Warren Ellis concluded his run on Stormwatch with the Final Orbit storyline which saw the team destroyed, Apollo was one of several Stormwatch characters he retained for his new Wildstorm title, The Authority. In it, Apollo (along with Midnighter) was recruited by Jenny Sparks for a new team, the Authority, under her leadership. The new series picked up themes Ellis had explored in Stormwatch, including the political potential of a team more powerful than world governments and the United Nations.

Apollo featured prominently in early story arcs, producing a miles-long wall of flame to contain super clones attacking London, rescuing civilians from disaster zones, and shooting down invaders from a parallel universe. In The Authority #10, Apollo sterilised the moon, killing the alien parasites that were using it as a base from which to attack Earth. He formed a friendship with leader Jenny Sparks, and his relationship with Midnighter was revealed in The Authority #8, written by Warren Ellis. For the portrayal of Apollo and Midnighter, The Authority received a GLAAD award.

The fourth Authority story arc saw Jenny Sparks die with the end of the 20th century and the Authority join a battle with U.S. government-backed superhumans to secure custody of her successor, Jennifer Quantum, the infant spirit of the 21st century. During this battle, Apollo was severely beaten by Storm God, a Thor pastiche, and The Commander, a Captain America pastiche. In one of author Mark Millar's most controversial scenes, it was implied that the beating was followed by a rape (The Authority #14). The rape was followed by a scene of revenge, in which it is implied that Midnighter raped the Commander with a jackhammer.

In another Millar-penned story, the Authority faced a rogue Doctor, intent on planetary destruction. Though this Doctor ultimately repented of his crimes, Apollo killed him with his eye-beams. Apollo featured also in the Transfer of Power storyline, in which the Authority was defeated, captured and usurped by sadistic, government-controlled replacements. Apollo was kept aboard the Carrier and brutalised by Midnighter's and his own replacements. The latter tried to rape Apollo before the real Midnighter returned to kill Apollo's assailant. Apollo himself then burned the head off Midnighter's replacement, later doing the same to the Machine, who had taken the powers of the Engineer.