While One Piece may appear as if it's just about a bunch of pirates and Marines punching and shooting at one another, there is a tactical mind behind every event. The strong may own a fight, but it is those who can take a step back that truly own the battlefield and, inevitably, the world. One Piece's brilliant minds are responsible for some of the grandest miracles in its world, even counting those of Devil Fruits.
This involves incredible advancements in medicine, a variety of mechanical inventions, or even just a tactical mind that can sway a battlefield. There is one question, however, that may even be too difficult for some of One Piece's most intelligent: Who truly is the smartest character?
10 Sengoku
While being the Fleet Admiral may not seem like the most scholarly position, it is a job that requires nothing less than a masterful strategist. Sengoku hasn't had a lot of time in the series to really show his stuff, but his most terrifying moments certainly weren't during his Buddha form.
It was when he hanged in the back and led and informed his soldiers, moving them around in such a tactical manner that they would be able to give pause to even Whitebeard's crew. His sense of strategy didn't go unnoticed as the pirates themselves acknowledged how slippery and conniving he could be just from the podium.
9 Nico Robin
Nico Robin was a prodigy in every sense of the word. Becoming not only an archaeologist but one familiar with a dead language is no easy feat, yet Nico Robin was able to accomplish both at a young age. This requires focus, patience, and a curious mind deserving of those who seek knowledge. However, that brain of hers is not going exclusively to reading a bunch of rocks.
Nico Robin is also a clever and tactical girl who has managed to infiltrate various organizations, sneak her way into secret thresholds, and move her way through battlefields without even being noticed. With both book and street smarts, Nico Robin was a great get for the Straw Hats.
8 Benn Beckman
Benn Beckman hasn't really had a lot of screen time in the series, so his placement here is just based on pure speculation. However, he has been described in the series to have the highest IQ out of anyone in the East Blue. That rating includes Captain Kuro, a man infamous for always having a thousand plans ready.
Such intelligence must've played a huge part in him becoming Shanks' first mate and devising the very plans that helped make the Red-Haired Pirates one of the most feared crews across the world.
7 Tony Tony Chopper
Tony Tony Chopper may be a cute face and a brutal fighter, but his true value lies in his medical expertise. Chopper is only 15 years old (in human years) but already has the proper qualities of an expert doctor. This is likely due to his inherent studiousness and drive to help anyone and everyone.
He trained under the revered Dr. Kureha and has expanded his knowledge throughout his adventures, particularly during the time skip and as Monkey D. Luffy's doctor. He's even devised a powerful drug that lets him use his Logia Fruit to its highest qualities, mutating different parts of his body to their peak forms. Who needs Awakening when Chopper has Rumble Balls?
6 Franky
Franky may look all muscle and pompadour, but his vibrant expressions and attitude only hide one of the most ambitious inventors and careful craftsmen in the entire world. Having trained on an island famous for its engineers and under the shipwright that made Gol D. Roger's ship, Franky became an exceptional shipwright who could not only help fix any ship but also build some powerful ones of his own.
His best works involved the architect's dream that is the Thousand Sunny, the various laser beams he's placed across his person, and the cyborg body that he gave himself (as well as the giant, mech suit on top of that).
5 Dr. Kureha
Drum Island is renowned for being a doctor's paradise, having developed a long line of the world's leading medical professionals. Even living within a country with that much fame, Dr. Kureha still manages to stand at the cold top as one of, if not the best, doctors in the kingdom.
She's a miraculous doctor who's managed to maintain a seemingly immortal disposition, can develop treatments at a snap, and can even read one's exact temperature with just a touch. Chopper may be a brilliant doctor, but he's still nowhere near as terrifyingly smart and skilled as the Sakura Kingdom's witch.
4 Dr. Hogback
Dr. Hogback may have been a Thriller Bark general at his best and a sniveling, stereotypical villain at this worst during his time, but it should never be underestimated what his role within the greater world was. According to Chopper, Dr. Hogback was a miracle surgeon who's famous for being able to cure and save any life at his disposal.
Far from being an easy task for someone presumably human, this would make Hogback a marvel within even the real world. His work gets a little grainier yet even more intriguing during his time on Thriller Bark, as he was the key player in creating Gecko Moriah's zombie army.
3 Caesar Clown
While Caesar Clown may have looked more like a comic relief during the latter end of his screen time, he is one of the One Piece world's most prominent, albeit controversial, scientific minds. Acting as even the second-in-command to Dr. Vegapunk, Caesar is a genius mind that even the World Government acknowledges but has now come to fear.
This is mostly because of his obsessive career with creating biological weapons and tendency to experiment on even children. Such endeavors, however, have allowed him to develop some of the most dangerous drugs and weapons in the world as well as turn regular humans into giants, something that even Vegapunk hasn't accomplished.
2 Vinsmoke Judge
Vinsmoke Judge may be known as perhaps the most despicable villain of the Whole Cake Island Arc, but his great size and brutal legend only hide one of the most profound scientists in One Piece. It's easy to forget that the big guy waving around a spear was once the equal and partner to the World Government's lead scientist, Dr. Vegapunk.
He's personally responsible for turning his own kids into super soldiers, developing power suits that would make superheroes proud, cloning a whole army within his lab, and running an entire country that sails across the sea.
1 Dr. Vegapunk
As it must be clear at this point, Dr. Vegapunk is probably the smartest and most influential scientist across all the Blues. He is a brilliant invention whose exploits go as far back as childhood, designing futuristic robots within his own room. He helped discover the applications for Sea Stone, the metal-like material that negates Devil Fruit abilities and is used by Marine ships to traverse the Calm Belt. He played a key role in learning about Devil Fruits, going as far as to invent a way to imbue weapons with Devil Fruit abilities.
He even invented the Pacifistas, a terrifying cyborg force that is not only equipped with incredible strength and a computing mind but also harnesses the strength of Bartholomew Kuma and the laser beams of Admiral Kizaru. He has yet to be revealed in the series, but his first appearance is already building up to be a special one.