2000 AD didn't even try to disguise B.L.A.I.R. 1 as anyone other than Tony Blair. Converted into a crimefighting cyborg with a built-in Robot Buddy called Doctor Spin, he used his hypnotic smile, super-strength and ability to take Spin's advice to make Britain great again by e.g. solving the unemployment crisis by sending single mothers down the coal mines.
Shazam! expy The Gentleman is modeled after Fred MacMurray (who has always been co-creator Alex Ross' model for Captain Marvel), while his sidekick Young Gentleman is modeled after Elvis Presley (a huge real-life fan of CM Junior).
Similarly, his daughter Matilda "Tillie" Armstrong is modeled after Judy Garland (in a nod to Mary Marvel originally being modeled after Garland.)
The Green Man, in addition to being a Swamp Thing Captain Ersatz, is also heavily inspired in appearance by Alan Moore, the best-known writer of Swamp Thing.
The British villain The Headmaster of Crime is John Cleese in a monocle and mortarboard.
Tom O'Bedlam is essentially Tom Wolfe, immaculate white suit and all.
One of the scientists in "Resistance" is a blatant personification of Dr. Bunsen Honeydew.
Black Dynamite: Los Angeles Lakers player Paul "the Pole" Monroe takes his name from New York Knicks player Earl "the Pearl" Monroe. The real Monroe didn't die in a tragic slam dunk stunt gone wrong, though.
Cerebus: Even after outgrowing its Conan-parody beginning, the series continued to feature parody characters and thinly veiled celebrities, Lord Julius (Groucho Marx), Dirty Drew and Dirty Fleagle McGrew (Yosemite Sam) and Adam Weisshaupt (named after the historical figure credited with founding the Bavarian Illuminati). For extra efficiency, Dave Sim created an Elric parody and a Senator Claghorn/Foghorn Leghorn homage in the form of Elrod the Albino.
And on a meta level, two of the above characters, as well as Red Sophia (herself based on Red Sonja), and Astoria, are victims of this in-universe: Weisshaupt publishes a series of "Reads" that espouse his political agenda, with their names cleverly disguised as Red Sophina, Astonia, Lord Junius, and Cernebus.
Destroyer Duck was written by Jack Kirby and Steve Gerber, who were in a legal battle with Marvel at the time due to creator's rights issues. One creator who notably turned up his nose at them for this was John Byrne, who happily described himself as a cog in the company. Coincidentally, one of the antagonists in the comic was the Cogburn, an entity created by the evil MegaCorp to replace talented employees, that is noted to be extremely prideful of their nature as company men—but not only are they dumber than the employees they replace, they also have neither a spine nor genitalia.
Very common in Italian Disney Duck comics. Pratically every famous VIP from Real Life has his duck avatar (with little edit of the names) in the comic.
The first two issues of IDW Publishing's ongoing feature a character named "Archie Maplin", obviously based on Charlie Chaplin. Chaplin himself was originally supposed to appear in the story, however the publishers were unable to get the rights from his estate. (While they didn't technically need the rights to use a Historical Domain Character, they belatedly realised they did need the rights to the fictional character he portrayed. The writer said in an interview that if they'd seen the problem sooner, they could have used Chaplin and not had him in costume.)
The Eleventh Doctor's companion, chameleonic glam rock star John Johns (aka Xavi Moonburst, the Tall Pale Earl), is obviously David Bowie.
Pulp Proto-Superhero "Dr. Coffin" was secretly Del Manning, a screen actor who did his own horrifying realistic monster makeup, earning himself the nickname "Man of 500 Faces". So basically Lon Chaney, Sr., if Chaney faked his death and became a vigilante.
Groucho from Dylan Dog. Yes, it's even the same name, even if it's known to be just an actor playing the part all the time (even when sleeping). And Dylan himself is a sosia of Rupert Everett. The author Sclavi is famous for rip-offs.
Partway through Jack Kirby's Galactic Bounty Hunters, the action shifts to the life of comic book luminary Jack Berkley, a thinly-veiled Kirby stand-in. Note that the comic was co-written by Jack's daughter Lisa.
Dan Francisco in Judge Dredd rather resembles Barack Obama. During the "Mutants in Mega-City One" storyline, Rebellion even made "Vote Francisco - change we can believe in" campaign buttons.
This is very common in the Dreddverse. To list all the examples over the years would require its own page.
Repression features characters very strongly based on Alfred Hitchcock (Cedric Rockwich), Alma Reville (Thalia Dubois) and Grace Kelly (Faith Reilly).
In The Road to Kadath, crooner Dickie Duncan is a thinly veiled version of Bing Crosby, complete with pipe and yachtsman cap.
Aging rock musician Elston Gunn in Into the Past is based on Bob Dylan, with Gunn even doing a version of the 'cue card clip' from Dylan's "Subterranean Homesick Blues".
The Marvel finale of Mighty Mouse featured David Udderman, a bovine avatar of David Letterman. It also had Polly Shafer (a parrot as Paul Shafer) and Arsenio Hawk (Arsenio Hall).
The Powers comic that illustrates Small Name, Big Ego: "Ultimate Ego, the Living Planet looks a lot like John Byrne — but not enough for him to sue us!"
Robotech II The Sentinels: Dr. Emil Lang's character design had to be changed from his design in the original Macross series (where he appeared briefly). His Sentinels character design bears more than a passing resemblance to Charles Bronson. In one of the letters pages, the truth was revealed. Someone simply submitted a panel of Lang with a mustache drawn on him.
Lucas Lee of Scott Pilgrim is clearly based on JasonLee, in both name and appearance, and they are also both professional skateboarders who became actors.
In The Wicked + The Divine, virtually all of the incarnate gods have real-life pop star counterparts.
In the early 1970s, Gold Key attempted to give Sylvester the Cat a cousin named Clovis, whose facial features, dialogue and mannerisms were akin to Stan Laurel.
The first issue feature the dictator Hassan Kussein (who's most definitely not Saddam Hussein) getting his head exploded.
And then there's the character Kirby, who's essentially Jack Kirby's head planted on a roided-up Cable body.
In Chapter 3 of The Department of Truth, the parents of a kid who died in a school shooting are continuously harassed and threatened by fans of a Conspiracy Theorist who accuse their kid of being a crisis actor. While the talking head is never named, he sounds and looks an awful lot like Alex Jones from InfoWars.
as anyone other than Tony Blair. Converted into a crimefighting cyborg with a built-in Robot Buddy called Doctor Spin, he used his hypnotic smile, super-strength and ability to take Spin's advice to make Britain great again by e.g. solving the unemployment crisis by sending single mothers down the coal mines.