Sometimes overlaps with World's Strongest Man, especially when brute force or sheer firepower are what decides combat strength. The first variation of this trope typically appears in competitions, such as a martial arts, boxing, or wrestling, where combatants would be subject to a great many rules, as well as gender and weight restrictions. The second variation is extremely common in Shōnen, where Power Levels indicate combat capabilities and fighting spirit.
For this trope to apply, there has to be some sort of mention, whether subtle or outright, that this character is ranked as the best. If this character actually does lose to someone, they are usually a Superior Successor and are instantly promoted to the new #1 spot. This character is either the winner (or a main antagonist) in a Tournment Arc, a Combat by Champion or when There Can Be Only One. In works where the hero is going To Be a Master, the person who fits this trope would be the biggest challenge in achieving their goal.
Kenshiro of Fist of the North Star is the successor of Hokuto Shinken, quite possibly the most badass martial art in the world. Only a small handful of warriors have managed to match him in pure martial arts skill and power, or win their first major battle against him. Everyone else he fights either becomes an ally, escapes and lives to fight another day, or is already dead.
Ricardo Martinez is certainly this in the world of Featherweight boxing. He's been the champion of his weight class for years by the time of the story proper, and has never been defeated.
Takamura, however, is unquestionably this. Takamura was a nearly-invincible Badass even before he learned to box, but after learning, he's utterly dominated his competition (although he's had some very close fights). It's even his goal to conquer every single weight division, and he's already completed two (Junior Middleweight and Middleweight). Word of God says he's the single best boxer in the series, even over Martinez, above.
In Yu-Gi-Oh!: Each main character is this. Yugi, Jaden, Yusei and Yuma may have their records besmirched with a loss or two, but overall? They can and will defeat anyone.
In Dragon Ball, this is a title that's hard to call, because part of the story is about characters rising to meet challenges. However, in the very last battle with Majin Buu, Vegeta acknowledges that Goku is, indeed, the best.
In Afro Samurai, the Number One Headband is reserved for the best fighter on Earth, who can only be challenged for the title by someone who has the Number Two Headband - The Hero himself - and anyone can challenge him for that headband. Afro himself isn't so interested for the Number One Headband, though - he just wanted revenge because the wearer killed his father.
One Piece: There are many candidates for the strongest in the verse, but so far, we have these:
Edward "Whitebeard" Newgate: Explicitly called World's Strongest Man, and for good reason: His Devil Fruit power, the Quake Quake Fruit, can create giant earthquakes and tsunamis, and in the world mostly filled with water, it means giant disaster. Sengoku even notes that this power can potentially destroy the world itself. Aside from that, his natural strength is immense, being capable to stop a giant vessels on its track with one hand. It's also said that the Whitebeard we see nowadays is far from his prime.
Kaido "of the Beasts", one of the Four Emperors as Whitebeard above, is called "strongest creature in the world". It either implies that he's inhuman, or that he really is the strongest person since the revelation comes long after Whitebeard's death.
Sengoku, as a former Fleet Admiral of the Marines, is also considered as the strongest of the Marines. Helped by his Devil Fruit, Human Human Fruit Model Great Buddha which allows him to turn into a big golden Buddha statue with phenomenal powers.
Captain Sentomaru of the Marines claims to have "the strongest defense in the world", and it shows: None of Luffy's attack could harm him. Particularly because he's a skilled Haki user.
Soul Reapers give this person a specific title: Kenpachi. The current holder of this title is Zaraki Kenpachi, captain of the Eleventh Divison. However, Zaraki Kenpachi is also the epitome of Unskilled, but Strong since teaching him actual technique threatened to make him more powerful than anyone thought they could handle. His predecessor (the original Kenpachi) on the other hand is undoubtedly a great warrior when finally given the chance to show off. When these two fight (primarily to impart Zaraki w/ the techniques needed to fight a bigger threat), Zaraki is easily killed and revived over and over and over again because dying subconsciously allows him to unlock greater power.
Another contender is Commander Genryuusai Shigekuni Yamamoto, the leader of the Gotei 13. He is stated to be "the most powerful combatant in Soul Society" by many. However, it's never made explicitly clear how his power stacks up against characters like the Kenpachi(s), Yhwach, Ichigo, or Aizen. His overall ability is presumably higher, but none of those characters ever face him in a fair bout.
Levi from Attack on Titan. Don't let his short stature, lack of social skills, or the fact that he's such a Neat Freak delude you—he's acknowledged in-universe as "Humanity's Strongest Soldier" for a reason. He makes Mikasa of all people look like a Red Shirt, and was able to take on the Female Titan on his own. On top of that, his official data states his battle skills are 11 from a 1 to 10 scale.
In Grappler Baki, Baki father, Yojiro, is considered the most powerful creature of all time. Baki succeeds him, but never actually manages to defeat him—Yojiro simply passes the title down.
Lady Shiva is the first form of this trope. In terms of pure skill, she is practically unmatched in the DC Universe. In a fair duel, Shiva can defeat anyone, with only her Rival Richard Dragon and her own daughter demonstrating any actual potential to defeat her. However, seeing as she lives in the DC Universe, she doesn't stand a chance against a Superpower Lottery, and whenever a hero is forced to fight her, they typically use an Outside-the-Box Tactic to soften her up first or defeat her outright.
Batman, Memetic Badass that he is, can supposedly defeat anyone with "enough prep time". As such, he's the second form of this trope, at least within his own franchise. It's a bit questionable in the DC Universe as a whole.
Wonder Woman zig-zags between both forms of the trope. She's certainly the Amazon's greatest warrior, but other characters have been shown to defeat her in pure skill. However, she's also demonstrated that if she gets serious and trains enough, she can match anything anyone can throw at her.
Captain America is the trope picture for One-Man Army for a reason. He's known in comics as a brilliant fighter, strategist, and soldier to the point that even if he isn't the one to deliver the final blow, his people will win.
Captain Marvel (aka "Shazam") was considered this in his original publication in Fawcett Comics. After being acquired by DC Comics, however, he is generally considered one of the best, but has competition from his peers.
Big Bad Sinestro of the Green Lantern franchise is largely considered the greatest Lantern, and best warrior, of all time. The only one close to his level of power and skill is his protege, Hal Jordan.
The protagonist of the Undisputed series starts as a boxing champion, but graduates to mixed martial artist by the end of the second film after defeating "The Most Complete Fighter In The World", Yuri Boyka.
Achilles in the Troy film. This retelling Does In The Wizard and just portrays Achilles as so exceptionally skilled that he seems untouchable.
The pilots of the eponymous Top Gun Academy are stated to be the best of the best. This culminates in a rivalry between the protagonist, "Maverick" and "Iceman". Although Iceman is awarded the trophy for being the Academy's top graduate, both Commander "Viper" and Maverick's lover (an instructor) state that Maverick is probably better than Iceman due to his use of Outside The Box Tactics and unorthodox maneuvers.
In X-Wing: Wraith Squadron the New Meat pilots ask Wes Janson and Wedge Antilles who the best pilot in the galaxy is. After some deliberation Wes concludes that the only objective way to determine this is total kill count, which makes Wedge, the only pilot to survive both Death Star runs and whose flight crew has to paint his kill silhouettes in squadrons' worth so they'll all fit, the best pilot in history. As confirmed in the Jedi Academy Trilogy Wedge is explicitly not Force-sensitive, and yet through endless hours of experience he has a near-precognitive ability to predict what his target will do next. He's also proven himself a fine tactician on multiple occasions.
Warrior Cats has Lionblaze, whose prophecy power makes him invincible in battle.
Commissar Ciaphas Cain of the Warhammer 40,000 novelverse is considered (by his editor Amberley Vail at least) to be one of the best swordsmen in the sector, "regardless of which sector he's in." The man is a Badass Normal who once fought a Chaos Space Marine to a standstill long enough for his aide to take it out with an anti-tank weapon. He's also a crack shot with his laspistol.
Edgar Rice Burroughs' Barsoom stories. John Carter of Mars is called the "greatest (or "master") swordsman in two worlds" (Mars and Earth) in The Chessmen of Mars, Llana of Gathol and Swords of Mars. His exploits in the series back up this statement.
In Book of Amber, Benedict is regarded by his family as the greatest warrior who has ever existed. No matter what the weapon, battle or terrain he will beat you.
Conan the Barbarian is wildly considered the most powerful man and the most dangerous warrior in the entire world.
Goliath was the best warrior of the Philistines, until he was killed by David with a rock and a sling.
Warhammer has Sigmar, a man whose prowess as a warrior not only allowed him to create an Empire of his own by uniting several warring tribes, but also become a Physical God of his own right. The Dwarves also deeply respect him after he saved their kind from a Goblin horde.
Mass Effect:Commander Shepard is the second version of this and is flat out stated to be the most lethal person in the galaxy, to the point that the Reapers themselves consider him/her the only serious threat they have. It gets to the point that even trying to take on Shepard gets someone dubbed as Too Dumb to Live.
Liu Kang, The Chosen One is picked to defend Earthrealm because he is the strongest human warrior.
Shang Tsung was the best warrior for 9 generations (450 years), but was defeated by the ancient Kung Lao before he could achieve Mortal Kombat. Kung Lao and then Goro repeated this feat, before Goro was finally defeated by Liu Kang.
The jury is out for Street Fighter on the male side, but Chun-Li is unquestionably the best female fighter.
In the Soul Series, Edge Master and Olcadan are the best fighters in the world. It's strongly implied that they managed to fight each other to a draw.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
Is that what you meant to do?
You are saying this draft has a ready-to-publish hat it does not deserve and you are taking it back.