%% This list of examples has been alphabetized. Please add your example in the proper place. Thanks!

* In summer 2010, the world was introduced to an ''Webcomic/AxeCop'' and [[Webcomic/TheAdventuresOfDrMcNinja Dr. McNinja]] crossover. And it was awesome.
* The kids from ''Webcomic/{{Precocious}}'' showed up in ''Webcomic/{{Curtailed}}'' for a few strips. Naturally, the author of ''Precocious'' reciprocated by featuring Fox and Seley.
* Also, in [[http://www.drunkduck.com/Dragon_City Dragon City]], there were four major crossovers from Jix. One was when an Ambis (the alien species from Jix) tried to take over the dragons' world, another instance when one of the villains tried to kill Erin because he thought the previous crossover was still disguised as her, one was when Jonas got kidnapped by one of Jix's minor villains, and the last was when Lauren and Jix saved Erin from her editor.
* ''Webcomic/EmergencyExit'' is quite famous for its ''very'' extensive crossover with ''Webcomic/ParallelDementia'', notably having a drastic effect on the plots of both series. It was also very, very long. ''Webcomic/EmergencyExit'' also had a crossover with ''Webcomic/BeyondReality'' before that (though that crossover didn't really effect the plot at all) and later had a second crossover with ''Parallel Dementia'' that consisted largely of Fall and Eddie having a conversation, with several big revelations made.
* ''[[Webcomic/EnsignSueMustDie Ensign Two: The Wrath of Sue]]'' takes this trope UpToEleven by having the cast traverse across most every alternate universe you can imagine. Characters and places of note are [[Series/DoctorWho the Tenth Doctor]], [[Franchise/{{Pokemon}} the Pokémon world]], [[Series/{{Sherlock}} Sherlock Holmes]], [[WesternAnimation/AvatarTheLastAirbender the world of Avatar]], and [[WesternAnimation/MyLittlePonyFriendshipIsMagic Ponyville]]. And that isn't even half of them.
* ''Webcomic/EvilPlanTheWebcomic'' had a brief and chilling crossover with the creator's other work [[http://sire.smackjeeves.com Sire]] as of Chapter 7.
* ''Webcomic/{{Fans}}'' had a crossover with ''Webcomic/PennyAndAggie'' recently, or at least the version of ''Penny and Aggie'' that exists in the Fans-verse. [[spoiler: Charlotte turns to dark magic during the story and after being taken into custody by Aegis, ends up reluctantly helping them in their fight against The Order.]]
* ''Webcomic/GeneralProtectionFault'' crossed over with ''Webcomic/KevinAndKell'' as [=GPF=] characters Nick and Ki landed in the K&K world.
* The main character in ''Webcomic/HereWolf'' debuted in the comic book ''ComicBook/{{Horndog}}'', and there are occasionally crossovers from time to time.
* It's been established in ''Webcomic/TheInexplicableAdventuresOfBob'' that Molly likes to write {{crack|Fic}} crossover {{fan fic}}s, like ''Literature/TheBrothersKaramazov'' meet ''Literature/HaroldAndThePurpleCrayon'' (Harold uses his purple crayon to break Dmitri out of a Siberian prison). One of her fics got illustrated to appear on [[Webcomic/TheAdventuresOfDrMcNinja Dr. McNinja's]] website, [[http://drmcninja.com/wp-content/uploads/McNinj-2.jpg thusly.]]
** The strip itself has had brief cameos by characters from ''Webcomic/{{Melonpool}}, Webcomic/{{Zortic}},'' ''Webcomic/EverydayHeroes,'' and ''Zeera the Space Pirate.''
* ''Webcomic/IrregularWebcomic'' does this from time to time, sometimes in ways you might not imagine.
* ''Webcomic/{{Jix}}'' has at least two crossovers from the creator's other series Dragon City. Both of which involve stories told about encounters with dragons, both of which were also mentioned in Dragon City, but without the Jix characters. Both times it involved main characters.
* ''Webcomic/KevinAndChad'': this comic crosses over with ''Jake n' Roxy'' (another comic by the author of THIS comic) in "Crossover".
* ''Webcomic/LeastICouldDo'' had a huge one with characters from every video game webcomic (and a few others), all fighting each other to the death. Rayne [[spoiler:died multiple times, but always came back due to them being clones.]] Combatants included ''Webcomic/DinosaurComics'', ''Webcomic/EightBitTheater'', ''Webcomic/LookingForGroup'', ''Webcomic/CtrlAltDel'', ''Webcomic/PennyArcade'', ''Webcomic/{{xkcd}}'', ''Webcomic/CyanideAndHappiness'', and many, ''many'' others. Also, John dressed as the ''Comicbook/GreenLantern'' and Rayne's car became a Franchise/{{Transformer|s}}. And he got it on with some superhero babes.
** Sadly, the long-awaited battle between [[Webcomic/EightBitTheater Black Mage]] and [[Webcomic/LookingforGroup Richard the Warlock]] never happened since they were apparently on the same side, but 's not to say it never will. You never know with Sohmer and Lar.
*** Props if you noticed [[spoiler: the background of the first ''8-Bit Theater'' in Rayne and John's apartment window on one of the pages.]]
* The eponymous characters from ''Webcomic/M9Girls'' have met characters from several members of the Website/WebcomicUnderdogs, mostly as prose stories written by the M9 Girls author:
** Clau got a bittersweet date with Sifo Kubek of Webcomic/TheDemonArchives, by means of [[DimensionalTraveler dimensional travel]].
** Any visited the kingdom of Elysium at Webcomic/PrincessChroma.
** The M9 Girls find themselves at different sides of the conflict when they meet the gang of Webcomic/RubyNation, in a DarkerAndEdgier version of both stories.
** Karla and Vero date Dan and Mike of Webcomic/{{Cesium}}. Things don't go as planned for the graduate students.
** Larry and Stephanie from Webcomic/GroovyKinda open a dimensional portal onto the M9 Girls locker room. Things escalate fast. This crossover is considered canon in both comics.
*** They took it UpToEleven: a second crossover has a supporting character of Webcomic/GroovyKinda permanently moving to the ''Webcomic/M9Girls'' universe.
* ''WebComic/EerieCuties''[=/=]''WebComic/MagickChicks'': The latter is an ongoing UrbanFantasy SpinOff of the former. Between their SharedUniverse and characters from one making appearances in the other, it was inevitable that some of their plotlines would intersect.
** The first major crossover involved [[AloofDarkhairedGirl Layla]], who's one of the [[{{protagonist}} protagonists]] from ''Eerie Cuties'', meeting [[SmugSuper Faith]] [[http://www.magickchicks.com/strips-mc/pesky_cats_-_ec_crossover_strip Abbot]], who's one of the main characters from ''Magick Chicks''. Which culminated in a fight between the two, that was finally brought to a peaceful resolution thanks to [[GeniusDitz Tiffany's]] [[http://www.magickchicks.com/strips-mc/a_superhero intervention.]]
** And there was the time [[SugarAndIcePersonality Brooke]] (from ''EC'') met Faith's boyfriend, [[LoveableRogue Ash]], which lead to [[http://www.eeriecuties.com/strips-ec/top_of_my_class a friendly sparring match.]] At least, it ''was'', until he deliberately provoked her because he knew she was holding back on him [[TemptingFate and wanted to see what she was fully capable of.]] [[BullyingADragon It was a mistake that nearly cost him his life]], since he hadn't known that the girl he was eggin on was a 14 year old Melusine, who [[http://www.eeriecuties.com/strips-ec/do_you_feel_him_breathing could transform into giant constrictor.]]
* There's a crossover saga in ''Webcomic/SlimyThief'' where in each arc the main character, Aisha, interacts with other creator owned characters. Apparently portals are opening up in alternate dimensions and sucking characters into hers.
* ''Webcomic/SomethingPositive'' (and all of Randy's other strips by proxy except for ''Super Stupor''), ''Webcomic/QueenOfWands'' (and ''Webcomic/PunchAnPie'' by proxy), ''Webcomic/PennyAndAggie'', ''Webcomic/QuestionableContent'', ''Scandal Sheet!'', and ''Webcomic/GirlsWithSlingshots'' are all part of the same webcomic universe. Using S* P as a node, this is the beginning of the Grand Unified Webcomic Universe.
** [[http://www.shortpacked.com/2010/comic/book-12/01-dominus-jacobus/davan/ And now]], ''Webcomic/{{Shortpacked}}!'' and the rest of the Webcomic/WalkyVerse by proxy. (Although a previous [[http://www.questionablecontent.net/view.php?comic=1550 two]]-[[http://www.shortpacked.com/2009/comic/book-10/03-the-comedy-laugh/coffeehouse/ sided]] crossover between ''Shortpacked!'' and ''Webcomic/QuestionableContent'' had already unofficially put it into the S*P Multiverse.)
* One of the earliest webcomic crossovers was a week of strips in 1998 between ''Webcomic/UserFriendly'' and ''Webcomic/SluggyFreelance'' where Torg temps at the [=ISP=] while Riff ends up battling the Coffee Monster.
* ''ComicStrip/WhatsNewWithPhilAndDixie'' throws in [[http://www.airshipentertainment.com/growfcomic.php?date=20090315 a few ideas]].
--> TabletopGame/{{Deadlands}} is a game combining two unconnected categories - [[TheWestern Western]] and {{Horror}}. As a result of the popularity of this refreshing juxtaposition, we can expect a slew of new games created by [[JustForFun/XMeetsY stitching together]] various "best selling" categories. Here's a preview...
* A brief subtle cross over in ''Webcomic/TheWhiteboard'', a quantum coffee maker dinosaur from ''Webcomic/QuestionableContent'' pays a visit, [[http://www.the-whiteboard.com/autotwb1379.html here.]]
* ''WebComic/ParanormalMysterySquad'' is the sister comic to ''WebComic/VampireCheerleaders''. In the earlier volumes, characters from one would occasionally [[TheCameo make appearances in the other.]] Volume 3 was the ''"Vampire Cheerleaders Must Die!"'' arc, which [[http://www.vampirecheerleaders.net/strips-vc/the_first_blow pit them against each other]] in a full-scale [[http://www.vampirecheerleaders.net/strips-vc/mind_blown free-for-all style battle]] that ended with the cheerleaders being exposed as vampires and taken into costudy by PETM. Naturally, [[AndTheAdventureContinues it didn't stay that way...]]
* Slave.In.Utero, author of ''Webcomic/TowerOfGod'', was asked to do a promotional crossover for ''VideoGame/MapleStory'''s 9th year anniversary. [[https://orangemushroom.files.wordpress.com/2012/05/maplestory-vs-tower-of-god.png He delivered.]]