Romulus is a supervillain appearing in American comic books published by Marvel Comics. The character is featured in particular in those titles featuring Wolverine. He is a mutant and the leader of the Lupines, a species resembling humans that he claims evolved from canines instead of primates through convergent evolution. A shadowy character whose origin and motives remain a mystery, he is shown to have orchestrated most major events in the life of Wolverine, manipulating and controlling him for most of his life.

Created by writer Jeph Loeb and artist Simone Bianchi, the character first appeared obscured by shadow in Wolverine (vol. 3) #50 (March 2007), and made his first full appearance in Wolverine: Origins #39 (August 2009).

Romulus is first seen in several flashbacks that Wolverine experiences, later explained by Wild Child to have been induced by Romulus himself. He is shown leading the Lupines in prehistoric and barbaric times, being an emperor in Ancient Rome, as well as being the main force behind Weapon X.

Romulus took Daken from his dead mother's womb and raised him as a ruthless killer. Nick Fury revealed to Wolverine that Romulus has been manipulating people from his family's bloodline for centuries, and that he plans for Daken to become the next-generation Weapon X.

After Wolverine subdues Omega Red, he is captured by Wild Child, who reveals that Romulus made Logan and several villains battle each other, his agenda being vaguely described as him needing a successor. After Wolverine uses the Muramasa blade to kill Omega Red, Romulus reveals himself in front of him, prepared for battle with his claws extended. Wolverine attacks Romulus but is easily overpowered since he is only using the sword at this point. Romulus slashes and attacks Wolverine from the shadows as he reveals his plans. Telling Wolverine that everything has led up to this moment. Romulus is what Wolverine will become. Pushing Wolverine to the breaking point, he drops the sword and pops his claws, much to Romulus' amusement. However, Wolverine fights back and gains the upper hand. Wolverine defeats Romulus, but leaves him alive saying that he will return when he is ready to finish the job.

Wolverine decides to confront Romulus one last time, with the help of various other heroes and his son Daken. As Daken is about to kill Romulus, Logan has Cloak teleport him into the Darkforce Dimension. Wolverine considers killing Romulus, but decides to leave him stranded in the Darkforce.

However, thanks to Sabretooth's blackmailing life of Dagger, Romulus gets free from his prison. After a losing fight against Romulus, a mysterious woman with long red hair appears and tells Wolverine that the answers that he seeks are at the Weapon X facility. Following his fight with the Sabretooth clones, the mysterious woman appears to Wolverine again. She calls herself Remus and informs him that Romulus is her twin brother. Remus reveals to Wolverine that the Lupines were an elaborate hoax by Romulus to hide his real goal of creating a master race of mutants artificially enhanced by adamantium.

After tracking Romulus to his stronghold in Italy, Wolverine brutally attacks and incapacitates Sabretooth before confronting Romulus. Wolverine finds Romulus immersed within a tank similar to the one Wolverine was held in during the days of the Weapon X program. Wolverine breaks open the tank and mutilates Romulus' face, revealing that his bones have been bonded with adamantium. As Romulus heals, Wolverine asks what the purpose is of becoming an imitation of him. Romulus declares that he is not as he once was, as he has "taken the best from both Wolverine and Sabretooth". Romulus and Wolverine resume their battle with Wolverine ultimately proving victorious, resulting in Romulus being remanded to the Raft.