The Saint of Killers in Preacher had a powerful and deliberate resemblance to Lee Marvin, stated as deliberate by Garth Ennis in his introduction to the Ancient History collection that contained his origin story. The Reverend Jesse Custer himself resembles Jim Morrison.
The eponymous hero of the Italian comic Dylan Dog is based on Rupert Everett. Among the other characters, Kim is based on Kim Novak, and Professor Adam on Sean Connery. Groucho is a in-universe sosia (doppelganger) of Groucho Marx, complete with fake mustaches.
This even extends to the so-called "Bonellidi," that is, comic books imitating the format and style of Bonelli Comics. For example, obscure character Gordon Link is based on Kyle MacLachlan.
Dave Stevens did this an awful lot in The Rocketeer. For example, Cliff is Errol Flynn, his girlfriend Betty is pin-up model Bettie Page, Cliff's sleazy photographer rival is real-world porn photographer Ken Marcus, and second-storyline villain Lothar is Rondo Hatton.
Stevens modeled Cliff Secord after himself, not Errol Flynn. He mentioned this in several interviews. And Peevy was modeled after his friend and mentor Doug Wildey.
The Gentleman, like inspiration Captain Marvel (above), is modeled on Fred MacMurray. On a similar note, his daughter Tillie bears a strong resemblance to Judy Garland, the original inspiration for Mary Marvel.
Since in Marvels, Reed Richards looked like Russell Johnson, Reed's Expy Augustus Furst also looks like Johnson. Augustus' brother, Julius, though, is based on Julius Schwartz.
Anything drawn by Greg Land will resemble a random assortment of celebrities and porn stars due to his tendency to trace. Unfortunately, there's little rhyme or reason to his choices. Emma Frost may look like Natalie Portman in one panel and Kim Kardashian in the next.
Cerebus the Aardvark has too many of these to count, though the most notable one has to be Lord Julius, who for all intents and purposes isGroucho Marx. Groucho's actual first name, for the record, was Julius. Other members of the Marx Brothers are also depicted. Over the years there has also been a character based upon Margaret Thatcher, and Canadian politicians have also been caricatured.
In Joss Whedon's Buffy the Vampire Slayer Season 8, there's a Tibetan character called Bayarmaa. The artist, Georges Jeanty, made her look like the exact portrait of Dichen Lachman, a half Tibetan actress who stars in another of Whedon's shows (she's Sierra in Dollhouse).
In "A Change of Mind", the villainous Mad Scientist Professor Hardin is both physically based on, and named after, Jerry Hardin, best known as Deep Throat in The X-Files.
Long-running Eighth Doctor companion Izzy S was based, according to Word of God, initially on the singer Louise Wener and later on the actress Luisa Bradshaw-White.
The Eighth Doctor strips also featured a fake Ninth Doctor, in reality, the Time Lord agent Shayde in disguise, who was visually based on the Big Name Fan, spin-off actor-director, and now official Dalek voice artist Nicholas Briggs.
Leighton Woodrow, a MI6 recurring character from that era of the comics, was closely based on Leo McKern, specifically, as he appeared when playing Number Two in The Prisoner (1967).
Frobisher's humanoid form in his Eighth Doctor reappearance is based on James Gandolfini.
In the Twelfth Doctor strips, Jess Collins was based on actress MéLissa Azombo, a big Doctor Who fan who jumped at the chance to be in the comic, even doing a photoshoot as reference for artist David A. Roach.
Tech-bro quadrillionaire Rudy Zoom, a recurring character in the Twelfth Doctor strips, is closely based on Lenny Henry (who'd subsequently get a role in "Spyfall" as wealthy tech-bro Daniel Barton, though he's a villain where Rudy's more or less on the Doctor's side).
The younger version of the War Doctor seen in The Clockwise War and Ambush is obviously based on a young John Hurt-specifically the picture used for his reflection in "The Night of the Doctor".
In the Eleventh Doctor comics, the older version of recurring villain August Hart is blatantly based on Bryan Cranston's Beard of Evil look as Walter White.
In the Twelfth Doctor comics, the original companion Hattie, who is a bassist in a rock band, looks like a younger and punker Gail Ann Dorsey, a real bass player best known for her work with David Bowie.
In the Thirteenth Doctor comics, the female incarnation of the Corsair who appears in one arc bears a strong resemblance to Katie McGrath.
There are a number of examples in Global Frequency, Depending on the Artist. In certain issues, Miranda Zero looks almost exactly like Michelle Forbes, who was later cast as her in the abortive TV pilot. In issue 4, the English gunwoman looks like Kate Moss (something of an in-joke, as Warren Ellis's Stormwatch and The Authority leading character Jenny Sparks was famously visually based on her). And in issue 5, the magician Alan Crowe looks exactly like Alan Cumming.
Rasputin in Corto Maltese is quite obviously modeled after the famous Russian monk of the same name. This is lampshaded in one story, where someone asks the name of the "guy who looks like Rasputin".
The main character of Switchblade Honey, Captain John Ryder, is based on Ray Winstone. The story started out with the idea "What if the kind of character who Ray Winstone usually plays somehow got to be a Star Trek captain?".
In the Marsupilami comic series, Harold Stonelove, the villain of "The Temple of Boavista", has a striking similarity to Hugh Laurie, especially in the flashback to his younger days.
Gargoyles: Several comic only characters were based on actors, and even the creator admitted that he mentally casts the characters. Quincy Hemings is Morgan Freeman, Duval is Eddie Marsan, and the leader of the Illuminati is Jude Law.
Jonathan Ross and Bryan Hitch's series America's Got Powers is pretty evident with its celebrity likenesses, with David Tennant as the head scientist, and Sarah Palin as a villainous US Sentator, with Ed Harris playing a John McCain fashioned US President, even before he was cast as McCain for the TV movie Game Change.
Louis de Funès makes an appearance as an irritable little man who mistreats his underling... just like any of his roles.
From Hell: Inspector Abberline was modelled after Robbie Coltrane. Who amusingly was also in the movie, though Abberline himself was played by Johnny Depp.
In Transmetropolitan, Oscar Rossini is played by Patrick Stewart, who was a big fan of the comic and had been considered as potentially playing Spider Jerusalem in a failed film adaptation project.
By Word of God, the titular heroine of Albedo: Erma Felna EDF is basically a feline version of Helena Bonham Carter, albeit only in looks in a retroactive way, due to the Art Evolution Erma has suffered across the years, since she debuted many years before Carter began her career as an actress.
The IDW comic spin-off of Dirk Gently has a Dirk who looks very, very, similar to David Tennant. He's also costumed and styled in a way that creates the general impression that IDW were very upset about losing the Doctor Who comics license and are desperately trying to lure the readers into a new comic.
In The Invisibles, the Blind Chessplayer is sometimes drawn to look exactly like Richard E. Grant. After one of those occasions, his conversation with Dane in Dulce, Dane outright says that he looked like a well-known actor without mentioning who.
The Viz character Cockney Wanker was based on actor and comedian Mike Reid (best known for playing Frank Butcher in EastEnders).
Comic adaptations of the Oz series have a tendency to draw Dorothy not as Judy Garland, but the original casting choice of writer Frank Baum and producer Mervyn LeRoy, Shirley Temple.
In Apama - The Undiscovered Animal, main character Ilyia and his love interest Vica are modeled after actors Perren Hedderson and Jocelyn Wrzosek, who played their counterparts David and Robyn in the movie Hero Tomorrow.
Lost Girls:
Melinda Gebbie based the grown-up version of Alice Fairchild on two of her female heroes - Maggie Smith and Germaine Greer.
Druuna: Serpieri explains in the art album Druuna X that Druuna's looks are based on Valérie Kaprisky in the Erotic FilmLa Femme Publique. Facially, they're almost identical, but below the neck Serpieri made Druuna even curvier.
ORPHANIMO!!: The character Agent Andrea is modelled after a well-known Flemish actress, who plays a similar role in the series Flikken. And the kids in the orphans' class in the third album are based on Flemish TV presenters on a kids' channel.
