A Piltovan Chem-Baron who was active during Silco's reign over Zaun. He runs The Hush Company, a vast network of informants and fences that acts as a switchboard for any and all illicit activity in the undercity—including that of his fellow Chem-Barons.

Corina is a meticulous artist with ambitious dreams for Zaun's future, and aims to become the envy of Piltover's ruling houses and Zaun's warring chem-barons alike. She enjoys gathering deadly ingredients from the rare plants that she grows in her cultivair, her scars artfully concealed by fashionable accoutrements. Her current Magnum Opus is a rare flower that feeds on the volatile chemicals of the Zaun Grey. She is also the arch-nemesis of Sheriff Caitlyn Kiramman.

A chem-baron who spent his fortune on high-grade chemtech. He was killed by Urgot.

Eramis has occasionally made deals with Piltovan nobles, such as 2 Reggie of Clan Ferros.

A Chem-Baron who was active during Silco's reign over Zaun. His company, the Slickjaws, specializes in elimination services and purveys both weaponry (including poisons) and manpower for large-scale operations. He attempted to overthrow Silco in disaffection, but fell by the blade of Silco's right-hand Sevika.

In his youth, Karvyq fell in love with Aurelie of House Tariost. As their love was forbidden, her family had his hands cut off as punishment for his low standing. He replaced them with silver prosthetics, making him known as the Silverhanded. When Aurelie died, Karvyq had a thief steal her ashes, which he then tattooed onto his chest. In the modern age, Karvyq is known for his chemtech products, which are extremely sophisticated, and his intense hatred towards House Tariost.

A Chem-Baroness who was active during Silco's reign over Zaun. Her company, The Vyx, provides pleasure services in the undercity, catering to any impulse, persuasion, or inclination.

A chem-baron who terrorized the gutters of Zaun, Marko attempted to forcibly marry Lady Sofia of House Arvino so that he would inherit her family's wealth and influence in Piltover. He was assassinated by Camille of Clan Ferros before he could do so.

A chem-baron who lost both his arms in an explosion at one of his chem-refineries and had them replaced with mechanical prosthetics. His chemtech stock is one of the most popular blends in Zaun.

A chem-baronness who prefers to use manipulation instead of violence to achieve her goals. After being orphaned as a child and left with nothing but her name and her parents' alchemical research, she spent the next few decades building her own business empire by tying everyone's interests to her own and ultimately emerged as Zaun's wealthiest crime lord.
Her company, Glasc Industries, produces weaponry, prosthetics, and perfumes from an unique blend of chemicals developed by her parents.

A Chem-Baroness who was active during Silco's reign over Zaun. Her company, the Sludgerunners, manufactures chemtech devices for the denizens of the undercity. After her son was accidentally killed by Jayce Talis during a raid on one of her factories, she joined Finn in his attempt to overthrow Silco, but backed down after Sevika killed Finn. She has a custom Turbo Chemtank named after her.

An Ionian chem-baron known for his violent temperament, he has a reputation for bloody gang warfare and is disdainful towards his fellow chem-barons. Claiming lineage from an exiled caste of warriors from a distant land, he has plans far beyond his own territories and interests. He was also responsible for funding the super-soldier project that created the monster Zac.

A drug kingpin who formed the first generation of Chem-Barons and served as their leader. He introduced the drug shimmer to the Zaunite population. After ruling over the undercity for nearly a decade, he was accidentally killed by his adoptive daughter Jinx when she suffered a mental breakdown.

A Yordle Chem-Baron who was active during Silco's reign over Zaun. His company, the Scrap Hackers, performs cybernetic modifications both cosmetic or performative, from genome hacking to mech-exoskeletons.

A chem-baroness with many business interests in Piltover, she deals mainly into golem technology. Her ravaged body was dying, so she had her head transplanted to a hextech-powered replacement. She visits Piltover regularly for fluid baths and blood/oil transfusions.

A chem-baroness who served as the warden of the Dredge, a chemtech prison mine located underneath Zaun. She would sometimes offer freedom in return for a prisoner's tortured confession, which she granted with the edge of her blade. She was eventually forced to abandon the Dredge and flee to Piltover after a violent encounter with Urgot, who took control of the mine in her place.

A chem-baron who rose to power by murdering his boss and taking over his criminal empire. Armed with a pair of shock-batons, he is a ruthless killer who sees murder and mayhem as tools of the trade. He currently works for Glasc Industries.