One Star Wars comic short story shows how Lando lost the Millennium Falcon. When Han finally shows his face in the last panel, he has a bandage on his chin. This refers to Harrison Ford's scar in the same place, which he got in a car accident. (The scar also gets a nod in Indiana Jones and the Last Crusade, where its presence on Indy's chin is explained via childhood accident with a whip.)
A Dark Horse ComicsStar Wars story provided a What If? scenario that implied that the Star Wars and Indiana Jones franchises exist in the same universe. The story ends with Indy finding Han Solo's skeleton inside the remains of the Millennium Falcon, which crashed on Earth a long, long time ago.
The Harley and Ivy comic has an issue where the title characters head to Hollywood to hijack a live-action Batman film that is being made. Once there, the first thing the women do is tie up and gag the actors playing Batman and The Joker. Before being gagged, the man playing the Joker briefly quotes Luke Skywalker's dialogue from The Empire Strikes Back, which starred Mark Hamill, who also voiced the Joker in Batman: The Animated Series.
Similarly, when an adaptation of the '60 series villain King Tut made an appearance in the comics, he was given the first name Victor, after the actor who played the character in the '60s series, Victor Buono.
In the Carl Barks classic Lost In The Andes, Donald and his nephews find a hidden people in the Andes that speaks American English with a typical Southern Drawl accent. Donald introduces himself by walking up to one of them and slapping him on the back saying: "Hi! I'm from the South myself! South Burbank!" Disney had an animation studio in South Burbank - where they had made Donald Duck shorts, among other things...
One X-Men comic revealed that Wolverine likes the musical Oklahoma!!, largely because he admired the lead actor in the then-current Broadway run. That would be Hugh Jackman, then...
The second issue of The Savage Wolverine has a scene where Shanna the She-Devil mentions that she always thought Wolverine would be taller "Like that actor Hugh Jackman."
The fifth issue of the Ultimate Comics: X of Ultimate Marvel features a lengthy inner monologue from Ultimate Nick Fury. It starts off with the blibical quote by Jules in Pulp Fiction and Ultimate Nick mentions how much he's always liked that quote for some reason. The reason being that he's drawn to resemble Samuel L. Jackson.
Similarly, a one off joke had Fury claim that, had they made a film about his life, he'd want Samuel L. Jackson play him.
In an issue of Spider-Girl, Mary Jane noticed Dark Devil (Peter's clone's son that he doesn't know about) and noted to Peter that he looks a lot like himself. He replied jokingly that the boy looked more like Tobey Maguire.
And, Deadpool had a more direct one, when talking about Spidey unmasking during Civil War, commenting that we all already knew it was Tobey Maguire under the mask.
Deadpool had been making that comment since before Civil War - when the two characters finally met.
And, what retroactively becomes an Actor Allusion was Deadpool's somewhat famous line 'If you looked like Ryan Reynolds crossed with a sharpie you'd understand'. Ryan Reynolds played Deadpool in X-Men Origins Wolverine, and will be doing so in Deadpool's spin-off film. This scene however predates that motion, though Reynolds was a fan of Deadpool for many years (can't imagine how amused he was after reading that panel) and had been trying to arrange a film to be made about Deadpool.
In one Mini Marvels comic, Wolverine is seen playing cards with The Brotherhood, consisting of Mystique, Sabretooth and Darth Maul. Both Darth Maul and Toad were played by Ray Park.
In Tintin, Professor Calculus' look is based on Professor Auguste Piccard, famous physicist and balloonist at the University of Brussels. When Bianca Castafiore is introduced to Calculus she mistakes him for a famous balloonist.
The Incredible Hulk. In a scene taking place inside Bruce Banner's mind, the fight for dominance appears as the "dumb" Hulk trying to push through a door that the "smart" Hulk is trying to keep closed.
Smart Hulk: (Slams door). Falls for it every time.
In IDW's Ghostbusters: Ongoing comic series, Ray has occasionally had dreams where he's visited by the ghost of Joliet Jake, who calls him "Brother" and gives him advice and warnings of things to come. These incidents are references to Ray's actor in the movies, Dan Aykroyd, who also played the other titular Blues Brother in those movies.