Jun does this for the famous Zutara pairing, starting first when Zuko asks her to track Aang with Katara's necklace, as she states "Aw, is it your girlfriend?" or something like that. Her second appearance causes an I'm Not Her Boyfriend moment.
Also Iroh, in one of the comics, briefly muses that perhaps Katara would be good for Zuko.
And whoever wrote the play in "Ember Island Players" was clearly a Zutarian, to the point that the characters were weirded out by it. While it upsets Aang, thinking if Katara does see him as a brother. While Katara is just confused about their relationship at the moment, due to the war.
As well as the infamous Saint Jun, we have the bald, tattooed criminals from "Avatar Day" who are apparently ship Kataang.
Azula ships Maiko. Azula jumped ship at the end of "Boiling Rock" but she was all for it before Zuko's Heel-Face Turn, because Zuko staying with Mai was, in her mind, the best way to keep him where she wants him.It works, but NOT in the way she expected... as Zuko leaves anyway and later Mai has a Heel-Face Turn for him. "I love Zuko more than I fear you!", indeed.
Let's not forget Sokka:
Sokka: Get in. We're going to save your boyfriend.
Katara: He's not my-
Even better in the French translation:
Katara: He's not my boyfriend.
Sokka: Not yet.
Even the Avatar Extras facts do this, as in the Big Damn Kiss that finishes off the series, a little bubble pops up that says "Kataang wins!"
This trope is Played for Laughs by Toph in the four-part series finale, where she seems to express herself as a Harutara shipper.
Toph: I knew it! You did have a secret thing with Haru!
Interestingly, Mako himself in one episode comes off as a shipper for Korra and his brother Bolin. Hilarious in hindsight considering Book One ends not just with Mako having feelings for Korra himself, but declaring his love for her.
Done in a roundabout way by Mary Jane. She goes to the school dance with Peter, but later meets and befriends Gwen when she transfers to Midtown High. Upon realizing that Gwen has feelings for Peter, she gives her a pep talk which helps convince Gwen to spontaneously kiss Peter in the season 1 finale. She continues to support the possibility of a pairing between them throughout season 2.
Aunt May, however, seems to ship Peter/Mary Jane from the moment she meets the girl, needling her nephew to meet her. She ultimately is the one who arranges that one date they had, by convincing Betty (who's twenty) that she's too old to go with Peter and then arranging Mary Jane to go behind his back.
Peter: Aunt May, you're an evil mastermind!
What about Keef in the unfinished episode, "Return of Keef" of Invader Zim. That guy is... ...very obsessed over the Zim/Dib pairing...
Ron being kissed by Kim often makes his naked mole rat Rufus say "awww" in response. By comparison, he acts disgusted if Ron gets kissed by a different girl. And at the end of the movie, when they finally get together, but are still a little shy about it, he pushes them together to start them dancing.
Even the villains seem to ship the heroes, in A Very Possible Christmas Drakken apparently ships Kim/Ron, even pushing them together under mistletoe (it was actually parsley) as soon as Kim arrives; Shego ships Josh/Kim in Blush and then Kim/Ron in Graduation.
In the Grand Finale, Drakken's symbiotic flower ships Drakken and Shego together.
Kim's mom also seemed to secretly ship Kim/Ron for the first three seasons. Became not-so-secret in So the Drama.
The live-action film gives an odd inversion to this, in that Cosmo and Wanda spend much of the first half of the film trying to prevent Timmy and Tootie from getting together, since it would mean Timmy would officially be grown up and they'd have to leave him. This eventually begins to change after Poof brings them to realize it's wrong to prevent Timmy from growing up, and by the end of the film, they're happy that Timmy and Tootie are finally together.
Cody helps his friend Trent hook up with Gwen, even though he also has a crush on her. In the same vein, Geoff and DJ could both tell that their friend Duncan and Courtney liked each other and playfully teased her about it.
Duncan and DJ both gave Owen/Izzy a thumbs up in the 19th episode.
Fanon often includes stories where characters play matchmaker for Noah and Cody. Usually includes Izzy, probably because on the show she once teased Noah about this.
On Total Drama World Tour, pretty much everyone (Gwen, Bridgette, Izzy, sort-of Heather) seems to ship Cody with Sierra...except Cody, who has a crush on Gwen. Tyler seems to like that pairing, though, since he helped Cody get a picture with her.
Noah seems to ship Tyler/Lindsay, since he once offered Tyler advice about it. He also seems to have a talent at sensing attraction between people, since he noticed Alejandro's crush on Heather before anybody else.
Sierra seems to have supported Duncan/Gwen before they got together, no doubt in part because it would free up Cody to be with her. However, when they actually got together by making out behind Courtney's back, Sierra turns against them. (Though again, her animosity toward Gwen may be at least partially because Cody did notAbandon Shipping when he found out, continuing to support and hit on Gwen despite her being in a relationship with somebody else.)
And in Teen Titans Go!, the comics based off of the Western Animation, Starfire seems to ship Beast Boy/Raven. "Perhaps Raven was teleported into an alternate dimension where she and Beast Boy are madly in love and ask me to be their maid of the bride at their matrimonial ceremony?"
In a later edition, Larry the Titan tries to be this for all the Titans, and steals Cupid's (Eros's) arrows to do so, resulting in a series of love-gushing couples (but nothing canon) ranging from the understandable to the completely bizarre. In fact, the whole reason he did this was because of the Robin/Starfire moment in Tokyo above.
"Is it just me, or is there something going on between those two? Will Green Lantern ever admit to his feelings? Will Hawkgirl ever stop sublimating her passions with that big honkin' mace?! Will True Love conquer all? Not on my show!" *BOOM*
Everyone who finds out Helga's deep dark secret on Hey Arnold! seems to be rooting for her. Her best friend Phoebe and Arnold's Grandpa Phil (who married a former childhood bully himself) will occasionally try to help lead Arnold in the right direction.
Don't forget Lila. As much as some fans like to go the Die for Our Ship route because Arnold likes her, in the play episode Lila is willing to drop out of her role as Juliet just so Helga can get the part opposite him. Lila does not like Arnold that way, and is more than happy to have him get together with someone who does.
Danny Phantom: Tucker ships his best friends, Danny and Sam, long before either of them starts to realize their feelings for one another.
Not to mention Danny's Parents, the kids at his school, even Danny's ghost enemies ship them together at one point or another.
Yumi's little brother Hiroki ships Yumi and Ulrich. He makes several comments throughout the series, including one where Ulrich was fighting a Krabe that had entered the real world, and he shouts, "This is so awesome! I keep telling you, you gotta go out with this guy!" In a public street, in front of Yumi, Ulrich and both of Yumi's parents.
Also, despite what Ho Yay fans might tell, Odd is definitely a Ulrich/Yumi shipper, even trying to advise Ulrich on the subject. Of course, Ulrich never follows his advices.
For about the first three seasons of Daria, Jane shipped her brother Trent with her best friend Daria.
In "Write Where It Hurts", Daria's last story has Quinn married to Jaime, one of her three constant suitors, while in another story Jesse is apparently dating Jane. Of course, yet another story had Jane/Kevin in a Graduate Homage Shot (with Kevin as Elaine), so these probably shouldn't be taken too seriously.
Gunther apparently liked seeing Kick kiss Kendall in "Box Office Blitz".
In "For the Love of Gunther", Kick tried to help Gunther hooking up with with Jackie - partly to get rid of her, but also because he wanted to help his friend.
At the end of "Dancing With the Enemy", Kick and Kendall are having a very affectionate moment, until someone in the crowd shouts "Kiss her!" This, of course, is their cue to go back to acting as if they hate each other.
Miss Martian and Artemis in Young Justice take turns trying to ship the other with another team member (Miss Martian with Aqualad and Artemis with Kid Flash). But it was only to turn the other away from their mutual interest: Superboy.
In season two, Megan's "little brother" Beast Boy ships her with Superboy, even though they've broken up at this point.
Kent Nelson shipped Artemis and Wally together long before they actually got together for real. His last words to Wally were to find his own spitfire like his own wife Inza, who never let Kent get away with anything.
Robin [about Miss Martian and Superboy being together]: "You know that they're a couple, right?"
Aqualad: "I believe I knew it before they did!"
In season two, Black Manta, of all people ships Aqualad/Tigress (Artemis)—he thinks they're a couple, and he clearly approves.
In Xiaolin Showdown, the good version Jack appears to ship Raimundo/Kimiko, even dragging Raimundo over to her and placing his hand on her shoulder in Time after Time. Their reactions imply that this isn't the first time he's done this.
On South Park episode Cartman Finds Love, Cartman becomes obsessed with pairing up new girl Nichole and Token, since they're both black. So much so, in fact, that when he learns Nichole has a crush on Kyle (and vice versa), he tells her that he and Kyle are a gay couple. He even follows Kyle on his date with Nichole, professes his love for him over the megascreen and serenades him with John Michael Montgomrry's "I Swear" just so Nichole and Token can be together.
Archer's Pam seems to ship Archer and Lana and Cyril and Lana. She's shown to disprove of Cyril cheating on Lana in the first season and guilts Cheryl for initiating their affairs. She later encourages him to spy on Lana and Archer during a mission, mostly so she can spy on Archer and Lana in the hopes of watching have sex. Cheryl also teases Cyril about Archer and Lana hooking up, but this is likely just to mess with him.
In Angel's Friends, the Big Bad ships Raf and Sulfus, since Raf is an angel and Sulfus is a demon, and their getting together would free her from her prison.
In Teenage Mutant Ninja Turtles (2012), a newly woken April perks up and demands all the squeeworthy details when she finds out that Leonardo has met a girl. She's clearly ready and willing to support him and his new love interest (possibly understanding that this is something he can't tell his brothers). Then she finds out that the girl he's talking about is a member of the evil Foot Clan, and proceeds to show him her disapproval.
In Generator Rex, Rex hints to Six at the end of A Family Holiday and Riddle of the Sphinx that Six and Holiday should get together.
As some fanfics of The Powerpuff Girls fabricated a romance between Professor Utonium and the girls' teacher Miss Keane, the episode Keen On Keane had the girls themselves play matchmaker for the two. Appeared to be a match made in heaven until the two were more focused on each other than their duties. And then when the Professor saw that Miss Keane had a cat, the romance was off as the Professor had a bad time with a cat before (episode "Cat Man Do").
In the season 3 premiere of Superjail!, Jared and Charise act as this to the idea of the Warden and the Mistress getting together and try to manipulate them into having sex to do so. Although, it's more for their own sake, as they feel if their bosses get together, they themselves will be able to be together in a united jail. Unfortunately for them, their plan is sunk when it turns out that the Warden has no clue how to have sex, leaving Alice to sleep with the Mistress and cause her to abandon the idea of wanting to rule the jail.