The Confidant

By their nature, characters have problems, issues, traumas, and sundry emotional baggage they need to lay down, even if only for a moment. However, finding someone to confide in isn't easy. Some don't care about anyone else's problems but their own, some characters feel they can't trust their secrets to others (or outright know telling anyone they know their problem won't end well), and a few feel that no one can really understand what troubles them.

Enter The Confidant. He or she or it (statuary and inanimate objects can serve this purpose, as can pets) is the one person that the character can confide in. The Confidant doesn't just listen though; they understand and keep the secret, no matter how much it sucks. They may or may not have profound, sensible, or well reasoned advice; sometimes just listening can help the character achieve an epiphanic Eureka Moment. The Confidant can be any cast member or a one time only character. Interestingly, The Confidant isn't necessarily everyone's Confidant; there may be a daisy chain of confidants in the story.

For extra kicks, they might be a powerful or influential person who proceeds to use their connections to help the character. Though usually a Nice Guy or gal, even a Jerkass can show a softer side this way. The Bartender is often saddled with this as a professional hazard, whereas the Chatty Hairdresser tends to treat their customers as their confidant. Often a trait of the Fixer Sue. She is always there to listen to everyone's problems, even people who wouldn't ordinarily admit they had any problems to themselves, much less admit them to another person, and Mary-Sue fixes them single-handedly. For these reasons, The Confidant provides a good way to get a character to spill out their guts without necessarily monologuing about how That Makes Me Feel Angry.

Naturally, this is a common form of The Reliable One.

This Stock Character was used in ancient Greek drama, which makes it Older Than Feudalism.

Anime and Manga

 * In Saint Beast, Luca fulfils this role for Judas. Being The Quiet One and The Lancer, he makes a specialty of it.

Literature

 * In the Heralds of Valdemar series, this is the primary purpose of the Monarch's Own Herald. The position was established soon after the founding of Valdemar as a way to give the Monarch, who as a Herald him/herself would feel The Chains of Commanding most forcefully, an absolutely trustworthy and incorruptible advisor. Queen's Own Talia exemplifies this, with the added bonus of being The Empath so Selenay doesn't even have to tell her how she feels.
 * In Dragaera there are the Discreets, people trained to be the confidants of the powerful.
 * On the Discworld, witches typically fill the role of confidant in their towns.
 * In The Wheel of Time, Min is this for Rand throughout much of the books. Whether he is ranting or thinking out loud, she is always there for him - sometimes just listening, sometimes giving advice or opinions. As she does not have any political or power agenda of her own, this is one of her primary functions in the series. As Rand slowly goes insane, she is among the last that he ever suspects of being against him (obviously a large reason for that is because ).
 * Dido's sister Anna in the Aeneid. Such an archetype of this trope that Shakespeare referenced it in The Taming of the Shrew; see "Theater" below.
 * Jeeves to Bertie in Jeeves and Wooster. Additionally, Bertie to most of his friends, although it's often because they're hoping to get Jeeves' advice and assistance secondhand.

Live Action TV
"Coach: It's a problem of communication. Here's what you do you get home, andyou sit the kids down, and you say to your boy - what's your boy's name? Leo: Ron. Coach: Uh, Ron. What's Ron's fiancee's name? Leo: Rick. Coach: Rick... here's what you say you say, "Rick, Ron..." Rick and Ron?"
 * One time on Cheers a guy came in looking for Gus, a bartender that used to work there, because he had a big problem that the other bartender would be able to help with. But Gus hadn't worked there for years. Finally Coach got sick of the guy going on and on about how great the other bartender was and took on solving the guy's problem himself. It involves the man's son and his fiancee, who is black.

Meanwhile, he is also Barbara Havers' confidant, where the issue is much more straightforward - he is the only person she has to confide in, period.
 * On Supernatural Bobby got sick of Sam & Dean leaning on him all the time, especially when he had his own problem - Crowley (a Middle Management Mook type demon) had his soul.
 * On Glee, Quinn and Kurt become Confidants for . Both of them find ways to help , and keep   secret even under extreme pressure when the WMHS rumour-mill starts turning in extremely unflattering fashion to all three.
 * Niles Crane from Frasier often plays this role, usually towards his titular older brother and anyone who has a problem with said older brother. Almost every time Frasier gets into trouble, his very first reaction is to go running to find Niles in order to spill the whole story and/or ask for advice, which Niles always genuinely and thoughtfully (though sarcastically) delivers.
 * Inspector Lynley has his confidant in his partner Sergeant Havers. Although he has other close friends in the show, two of them are Brother Chucked after the pilot and the other is his wife - who he either can't confide in because his issues have to do with her, or won't confide in about anything else for any number of other reasons.
 * Buffy the Vampire Slayer: Tara becomes this to the Slayer over her destructive love affair with Spike. Buffy is so traumatized that she had basically become her arch enemy Faith that she begs not to be forgiven.
 * Spike himself acts in this role at the beginning of the season; a sign that she's drawn more towards him than to her friends. Spike offers an alternate explanation in "Once More With Feeling" -- the fact that he's a vampire means that Buffy can tell herself her confessions to Spike aren't real like confiding to her friends would be.

Theater
""...And now in plainness do confess to thee That art to me as secret and as dear As Anna to the Queen of Carthage was,
 * Tranio to Lucentio in The Taming of the Shrew.

Tranio, I burn, I pine, I perish, Tranio,

If I achieve not this young modest girl.

Counsel me, Tranio, for I know thou canst.

Assist me, Tranio, for I know thou wilt.""

Video Games

 * Hotel Dusk: Room 215's Kyle Hyde ends up doing this.

Western Animation

 * In ThunderCats (2011) Court Mage and Old Retainer Jaga suspects that young Rebel Prince Lion-O has seen a vision during a Rite of Passage, and is frightened of disclosing because of a reputation as a Cloudcuckoolander and family Black Sheep. To prompt Lion-O to confide in him, Jaga notes that legend says "... our greatest king will possess the ability of "Sight Beyond Sight." which prompts Lion-O to ask a Trial Balloon Question about visions. After a pep talk, Lion-O is won over, and says he has something to tell Jaga. Unfortunately, Jaga performs a subversion and decides that having won Lion-O's trust, the details can wait until after Lion-O attends a celebration. Neither knows Lion-O saw the face of an ancient enemy.