Mongul (/ˈmɒŋɡəl/) is a supervillain appearing in American comic books published by DC Comics. Writer Len Wein and artist Jim Starlin created the first version of the character, who debuted in DC Comics Presents #27 (November 1980). Jerry Ordway created the second version, who first appeared in The Adventures of Superman #454 as the lord of Warworld. He was later embellished by Peter Tomasi and Scot Eaton in Showcase '95, #8. He is based on the Mongol Empire's founder Genghis Khan and his successors, hence his name. The character was given an origin story in Green Lantern #23.2 by his co-creator Jim Starlin and artist Howard Porter as homage to the writers who participated in developing the character. He has become one of Superman's most enduring enemies belonging to the collective of adversaries that make up his rogues gallery.

Debuting in the Bronze Age of Comic Books, Mongul has been featured in other DC Comics-endorsed products such as animated series, video games, a direct-to-DVD film, and merchandise such as action figures and trading cards.

Mongul debuted in the title DC Comics Presents and was created by writer Len Wein and artist Jim Starlin. Starlin often receives credit as creator of the character, but Wein in an interview stated: "Well, [Mongul] had Starlin visuals, but he was my creation". Wein said he conceived Mongul specifically as a villain to physically challenge Superman. Starlin commented on the character as well stating, "When I went over to DC... I went over and created Mongul and he was definitely supposed to be Thanos in the DC universe"

Mongul was the ruler of his species until a revolution occurred by his people and a holy man named the Ancient Arkymandryte. Mongul was forced to flee the throne to save his life. In his first appearance, Mongul kidnaps Superman's friends (Lois Lane, Jimmy Olsen, and Steve Lombard), threatening to kill them unless the hero brings him the key from a dead Warzoon race called Largas, that can activate the artificial planet Warworld. After Superman retrieves the key, and is forced to fight Martian Manhunter who is protecting it, Mongul activates Warworld. Psychically linked with its controls, Mongul tries to destroy Superman and Supergirl. Mongul is ultimately rendered unconscious by the mental strain caused from using its controls, but manages to escape before the heroes destroy Warworld.

Mongul then tries to conquer Throneworld, the home planet of Prince Gavyn, one of the heroes who have used the name Starman. Mongul murders Gavyn's sister and forces Gavyn's lover into marrying him to usurp the throne of the empire for himself. He uses Throneworld's planet-destroying weapon to blackmail other planets into obedience. Superman arrives and battles Mongul, while Starman disables the weapon. Mongul retreats as soon as the weapon is disabled, planning to make his next move. Now wanting revenge on Superman, Mongul kills a Controller and steals a Sun-Eater to devour the Earth's Sun. While the Justice League of America and Legion of Super-Heroes battle Mongul, Superman finally defeats him as the Legion destroys the Sun-Eater. Mongul attacks Superman on his birthday and ensnares him with Black Mercy, an alien plant that feeds off a victim's "bio-aura" and subdues them with visions of their ideal world. Meanwhile, Mongul nearly kills Wonder Woman while mocking her views that women are equal. In the end, thanks to Batman, Robin, and Wonder Woman, Mongul falls victim to the plant, receiving visions of being ruler of the universe.

Following the limited series Crisis on Infinite Earths, which rebooted DC's continuity, Mongul is reintroduced as the ruler of Warworld, a space empire where he entertains the citizens with gladiatorial games. Mongul's ship captures a dying Superman, who was floating adrift in outer space after he exiled himself from Earth, and Mongul decides to use him in the games, but Superman joins forces with the alien warrior and Mongul's champion Draaga and makes Mongul flee. Mongul is then persuaded via torture to serve the Cyborg Superman to gain vengeance on Superman and to try to turn the Earth into another Warworld. In the process, Green Lantern Hal Jordan's home, Coast City, is destroyed, which leads to him joining Superman and his allies to defeat Mongul. After his defeat, Mongul is imprisoned in a prison for intergalactic criminals, only to break out during a riot.

During the Underworld Unleashed crossover event, the demon Neron offers various supervillains enhanced power in exchange for their souls. Mongul's pride causes him to decline the offer and threaten Neron. In response, Neron beats Mongul to death for his defiance, taking his soul in the process.

Mongul the Elder had twin children who survived: a boy and a girl. Both shared a strong sibling rivalry. The first, Mongal, was known for her physical strength, while the second, Mongul, was more rational than his sister. Mongul's son, also named Mongul, watched digital renderings of his father's battles with Superman and the destruction of Coast City. He copies his father's actions when he encounters a group of aliens whose spaceship crashes on Arkymandryte, turning them into his slaves. Mongul's father returns, and discovering his son's slaves, he kills the aliens and tells him only one being on the planet is worthy of adoration.