Cerebus (/ˈsɛrəbəs/; also Cerebus the Aardvark) is a comic book series, created by Canadian cartoonist Dave Sim, which ran from December 1977 until March 2004. The title character of the 300-issue series is an anthropomorphic aardvark who takes on a number of roles throughout the series –barbarian, prime minister, and pope among them. The series stands out for its experimentation in form and content, and for the dexterity of its artwork, especially after background artist Gerhard joined with the 65th issue. As the series progressed, it increasingly became a platform for Sim's controversial beliefs.

The comic began as a parody of sword and sorcery comics, primarily Marvel's version of Conan the Barbarian. However, it evolved to explore a variety of other topics, including politics, religion, and gender issues. At a total of 6,000 pages, it progressively became more serious and ambitious than its parodic roots. Sim announced early on that the series would end with the death of the title character. The story has a large cast of characters, many of which began as parodies of characters from comic books and popular culture.

Starting with the "High Society" storyline, the series became divided into self-contained "novels", which form parts of the overall story. The ten "novels" of the series have been collected in 16 books, known as "Cerebus phonebooks" for their resemblance, by way of their thickness, to telephone directories. At a time when the series was about 70% completed, celebrated comic book writer Alan Moore wrote: "Cerebus, as if I need to say so, is still to comic books what Hydrogen is to the Periodic Table".

Cerebus was self-published by Dave Sim under his Aardvark-Vanaheim, Inc. publishing banner. For the first few years the company's publisher was Deni Loubert, Sim's girlfriend (the two married and divorced during the comic's run). Sim's position as a pioneering self-publisher in comics inspired numerous writer/artists after him, most notably Jeff Smith (Bone), Terry Moore (Strangers in Paradise), and Martin Wagner (Hepcats).

In 1979, Sim, who was at the time a frequent marijuana user, began using LSD, taking the drug with such frequency that he was eventually hospitalized. It was this incident that Sim claims led to the inspiration to produce Cerebus for 300 monthly issues.

When Sim published the first Cerebus "phone book", a paperback collection of the High Society graphic novel (Issues #26–#50), he angered distributors—who felt that their support had been instrumental in his series' success in an industry generally indifferent to small publishers—by offering the first printing via mail order only. The decision was a financial windfall for Sim, however, grossing over $150,000 in sales (equivalent to $430,000 in 2024). Sim became known for picking up hotel tabs for self-publishers and helping other self-publishers by paying for meals and limo service between stops. Negotiations regarding DC buying Cerebus took place over the course of 1985 to 1988, offering $100,000 ($266,000 today) and 10% of all licensing and merchandising, which Sim rejected.

The series hit a personal sales record with issue #100 which, despite being a normal issue in the middle of a story arc, had a print run of 36,000 copies. Sales took a substantial drop over the next 50 issues, however, and Sim commented that the fact that readers could not simply "jump in" to Cerebus, and had to read the entire series in order to be able to understand the current issue, was a major reason for the sales drop.

In July 1984, Cerebus publisher Aardvark-Vanaheim was threatened with possible legal action by Marvel Comics over a parody of Wolverine in Cerebus.