First Appearance: Wyatt Earp #1 (November 1955).
Appearances: Gunsmoke Western #35-36, 43-58, Rawhide Kid #1, Wild Western #47, Wyatt Earp #1-34, Outlaw Kid #20, Black Rider Rides Again! #1, Kid Colt Outlaw #179, 186, Two-Gun Kid #121, Western Gunfighters #3, 5, 6.
Years Active: 1870s?-?
Wyatt Earp was a real person, of course, born 1848, died 1929, worked as a stagecoach driver and buffalo hunter, served as deputy marshall in Wichita and Dodge City, became friends with Bat Masterson and Doc Holliday, was part of the Gunfight at the OK Corral, gambled a lot, operated saloons in San Diego and Nome, Alaska, worked mining claims in the Mojave Desert, spent time in Los Angeles and befriended early Hollywood actors--quite a life, all things considered.
But the Wyatt Earp of the comics has little to do with the real Wyatt Earp, just like the Annie Oakley of the comics was only very loosely based on the real Annie Oakley. Unlike the Annie Oakley stories, however, the comic adventures of Wyatt Earp were serious, in the same vein as the Rawhide Kid and most of the other Atlas cowboy heroes. Too, it was specifically stated that the stories were based on "the adventures and legends of Wyatt Earp," so that there was rarely any doubt that what we were reading never actually happened.
Finally, there were actually two comic book Wyatt Earps. Well, there've been more than two; Earp being a real person, and dead, there's never been anything to prevent various comic book companies and writers from putting Earp into their comics. But there've been two Earps in various Atlas and Marvel comic book stories.
There's the first Earp, who appeared in the Atlas comics. He's a rather grim and serious man, rarely smiling, and active in a rough-hewn American West. He wears a black coat and a black hat wit a brown vest, set off by his thin black mustache. He's always a sheriff, but his locale changes to fit the story requirements. He is assisted by a grizzled deputy named Grizzly. Earp is a good shot, a quick draw, fair to all men, interested in justice and mercy, etc etc etc.
Then there's the second Earp, who appeared in the more recent Marvel comics. The second Wyatt Earp is significantly more light-hearted and smiling than the first Earp. The second Earp isn't exactly singing cowboy material, and is quite capable of being serious and even shooting men if the situation calls for it, but on the whole he's a lighter character, and the milieu in which he works a lighter, cleaner, more sanitized place, than that seen in the original Atlas comics. The second Earp lacks the sidekick Grizzly, and dresses in a floral vest rather than the sort of orange-ish vest of the first Wyatt Earp. Other than that, though, the second Earp is like the first, being a good man, good sheriff, good shot, etc etc etc.
Note: The two images at the right represent the two versions of Wyatt that appeared in Atlas/Marvel magazines. The one at the top is the "classic" Wyatt Earp, the one that (as far as I know) is closer to the original, real Wyatt Earp; all he lacks is the black overcoat that Earp was known to wear. (Note the pencil-thin Adolphe Menjou mustache, partially obscured by shadow.) The version at the bottom--lacking the mustache and wearing a flowery vest--is the cleaned-up version that appeared in later (1970s) Marvel comics.