The character of Superman was created by Jerry Siegel and Joe Shuster, and has been continually published in a variety of DC Comics book titles since its premiere in 1938. There have been several versions of Superman over the years, both as the main hero in the stories as well as several alternative versions.

In mainstream comic continuity Originally, there was only one Superman. However, beginning in the late 1940s, demand for comics shifted from superheroes as war, horror, science fiction and romance comics became more popular. Most of the DC Comics superhero titles were cancelled or began featuring the more popular genres. Superman, along with Batman and Wonder Woman, continued to be published. To explain how Superman could have been active as a young man in the 1930s when later stories show Superman still youthful in the 1960s, DC Comics developed a multiverse, the existence of several realities. The original Golden Age Superman was retconned to Earth-Two, while the then-currently published hero was assigned to Earth-One.

In addition to these main two "official" variations of the standard Superman character, a number of characters have assumed the title of Superman in many variant stories set in both primary and alternative continuity. Following the storyline of The Death of Superman and during the subsequent Reign of the Supermen storyline, a number of characters claimed the mantle. In addition, Bizarro, for instance, is an imperfect duplicate of Superman. Other members of Superman's family of characters have borne the Super- prefix, including Supergirl, Krypto the Superdog and, in some instances, Superwoman.

Pre-Crisis 1938–1986 Superman was first published in 1938. In 1986, DC Comics published Crisis on Infinite Earths, a 12-issue series designed to clean up and establish a new continuity for DC, affecting not only Superman, but all of the DC Comics characters. The versions of Superman from this time period are traditionally divided into three main periods.

Golden Age 1938–1950s The first version of Superman began being published by DC Comics in 1938 appearing in Action Comics #1. To explain discrepancies in the aging of Superman across several decades, his earliest stories were retroactively portrayed as having taken place on an alternate world called Earth-Two. This version of Superman was initially depicted with reduced abilities, being able to jump very high, but not capable of true flight. The Golden Age Superman (Kal-L) is the first primary superhero of Earth-Two, who began his career as an adult and emerges just before World War II. He is a member of the Justice Society and, during World War II, the All-Star Squadron. As Clark Kent, he works for the Daily Star as a reporter and eventually becomes editor-in-chief. Clark eventually marries Lois LaneAction Comics #484 (1978) and settles down with her for several decades, and when Kal-L's long-lost cousin Power Girl arrives on Earth, they become her surrogate parents.Infinite Crisis #2 (2006) Kal-L is erased from Earth's history after the events of Crisis on Infinite Earths, but survives and enters a "paradise" dimension. During the Infinite Crisis event, both Kal-L and the Earth-Two Lois are killed.Infinite Crisis #7 His main two foes are the Ultra-Humanite and the red-haired Lex Luthor. In addition, his "S" symbol on his chest is generally drawn in a less distinctive manner. Stories taking place in the 1970s and 1980s featuring this version of Superman are usually labelled as Earth-Two stories.

Silver Age 1950s–1971

The more significant differences between the Golden Age version (later equated with Kal-L of Earth-Two) and Silver Age version (Kal-El of Earth-One) of Superman includes the Silver Age Kal-El beginning his public, costumed career as Superboy at the age of eight,See, for example,The New Adventures of Superboy #1 (1980) and #12 (1980) more than a decade before nearly all other Earth-One heroes. Superboy only finds super-powered peers in the 30th-century Legion of Super-Heroes, though he also meets as a teenager Earth-One's only other major superpowered hero, "Aquaboy" (the teenaged Aquaman).Superboy (vol. 1) #171, January 1971 Lex Luthor meets Superboy in Smallville when they are teens; the two are briefly friends before they become mortal enemies, years before they become adults.Adventure Comics #271 (1960) As an adult, Clark Kent works at the Daily Planet and Superman is a founding member of the Justice League of America.

The Silver Age Superman was typically characterized as being more grounded in reality than previous depictions, in that he was portrayed with a realistic appearance and embedded within logical and rationalistic narratives. While these were still based on the science fiction of his earlier iterations, Superman was portrayed in storylines that sought to uncover the mysteries of the world through observation and the use of evidence, including the concept of limits and the consequences of human action. This definition is attributed to Curt Swan, who was the principal artist of Superman comics from 1955 to 1985. Swan's extensive work on the character, which was responsible for much of the public perception of the superhero, emphasized anatomical realism, embedding in the character a sense of Norman Rockwellesque Americana. This depiction of the superhero resonated with the readers as indicated in the way some observers saw their own lived experiences in his stories.

Bronze Age 1971–1986 In 1971, Dennis O'Neil and Julius Schwartz set out to simplify Superman's elaborate framework. They streamlined the Superman mythos by downsizing his abilities and reducing his power levels. This version only lasted a few issues.McAvennie, Michael; Dolan, Hannah, ed. (2010). "1970s". DC Comics Year By Year A Visual Chronicle. Dorling Kindersley. p. 144. . New editor Julius Schwartz, new scripter Denny O'Neil, and regular artist Curt Swan removed kryptonite, the Man of Steel's greatest weakness, from the face of the Earth. DC attempted more of a soft reboot in the 45th Anniversary issue of Action Comics. Lex Luthor and Brainiac were updated and modernized to make them more visibly dangerous for Superman.Action Comics vol. #1 #544–546 (June–August 1983) and Superman #385–386 (July–August 1983) The Silver/Bronze Age (Earth-One) Superman was given a send-off in the Alan Moore-penned "imaginary story" Whatever Happened to the Man of Tomorrow? (1986). Colloquially known as "The Last Superman Story", it was a conclusive ending to Superman's story as a character. The story was originally conceived by senior editor Julius Schwartz, who designed a goodbye for the hero in his final two Superman issues (prior to the John Byrne The Man of Steel relaunch) – Superman #423 and Action Comics #583 (1986). Both comics were illustrated by longtime Superman artist Curt Swan.

Other Pre-Crisis versions Before Crisis, the Multiverse was also used to explain an "evil" version of Superman from Earth-Three as well as other versions that officially existed. Earth-95 had Superman's father Jor-El rescue his entire family.Superboy vol. 1 #95 (1962) Earth-149 saw Lex Luthor succeed in killing Superman.Superman vol. 1 #149 (1961) Earth-Prime was designated as the "real" world, even though Superboy-Prime is from that universe. This version of Clark Kent is from a world without other superpowered beings, where he grows to adolescence reading about the DC superheroes in comic books. During the Crisis on Infinite Earths, he gains powers like those of the Silver Age Superboy and helps to defeat the Anti-Monitor. However, his own world is lost and Superboy-Prime is confined to another dimension.

In addition to official versions, other stories listed as "What Ifs" or imaginary stories which were not originally an official part of DC continuity. One example, Superman Red/Superman Blue was the subject of several story lines. The Silver Age version of the tale was an "imaginary story" in which Superman splits into two beings, one which marries Lois Lane, and the other marries Lana Lang, and both are happy. Both retained their powers, with one having all red removed from his costume and the other having all blue removed. In Superman #300, a story imagines what would have happened if Superman had landed in the middle of the Cold War, with both the U.S. and the USSR trying to capture the capsule as it is landing. Kent is a reporter for a worldwide news service, and takes the name Skyboy.

Post-Crisis: 1986–present The multiverse was discarded in the aftermath of Crisis on Infinite Earths limited series (1986) by rebooting all of DC's various stories and continuities into one timeline taking place on a single Earth (later described as New Earth). A more modern adaptation of the mainstream "Earth-One" Superman debuted in John Byrne's The Man of Steel miniseries in 1986. The post-Crisis Superman was the Superman from 1986 to 2011. Superman's backstory was heavily revised and many Silver Age elements, such as his career as Superboy, were removed.Man of Steel #1 (1986) Significant changes included a reimagining of all Kryptonians being genetically bound to Krypton, making it fatal for them to leave the planet. Jor-El devises a serum to counter this, which he administers to baby Kal-El. DC used this plot device to make Superman Krypton's sole survivor until this was retconned in the mid 2000s to introduce the post-Crisis Kara Zor-El. Krypton was also reimagined as an emotionless and sterile society where all children are grown in a birthing matrix as Kryptonians find sexual reproduction to be barbaric. Clark only becomes Superman as an adult, eliminating his time as Superboy from continuity. Other differences include Lex Luthor as a business mogul with secret criminal dealings rather than a supergenius scientist who is a known crook to the public; both of his parents alive and well in the present; only green kryptonite existing (until the mid 2000s) and Superman thinking of himself as Clark Kent first, with "Superman" being a persona he adopts to preserve his privacy. Nuances in the characters mythos were later defined in various Superman origin stories, such as Superman: Birthright, where Mark Waid retooled Superman's origin in 2003. The trend continued after Infinite Crisis; when Superman's backstory was retooled once again by Geoff Johns, with Superman: Secret Origin in 2009.

The single-Earth continuity retained the dichotomy of a good and evil Superman by introducing an alternate version of Superman's Earth-Three double, Ultraman in the Antimatter Universe surviving the Crisis, as presented in JLA: Earth 2. Alternative Supermen were also depicted using literary devices such as time travel and "Hypertime". The subsequent sequel to Crisis, titled Infinite Crisis, saw the return of the Golden Age Superman, Kal-L as well as Superboy-Prime. The modern take on the Superman Blue/Red was a controversial storyline in which Superman develops energy-based powers while losing his original powers, and acquires a corresponding new costume. He eventually splits into two versions of the energy-Superman, known as Superman Red and Superman Blue, before the two Supermen manage to find a way to work together and merge back into one entity.