Kyle Broflovski
Kyle Broflovski is a main character in the animated television series South Park. He is voiced by and loosely based on co-creator Matt Stone. Too much favoring towards Cartman. Sure he's good at planning and executing schemes when seeking for revenge but that's it. Kyle has the wide knowledge subjects and is very smart in class
Kyle is better than Bebe. Bebe Stevens is a hypocrite and a coward and a racist about putting Jews in the bottom list which makes her wrong! Kyle is the best, Bebe is annoying and is the worst!
Kyle is one of the smartest kids in South Park. He may not be a 'schemer' like Cartman, but he knows the rights and wrongs in situations and gets great grades.
Eric Cartman
Eric Theodore Cartman, often referred to just by his surname, is a main character, as well as a major antagonist and occasional antihero in the animated television series South Park, created by Matt Stone and Trey Parker, and voiced by Parker. He is one of four central characters in South Park, along... read more Sure he gets ridiculous grades and needs a MONKEY to spell, but he planned out a kid EATING his own PARENTS, broke into the Pentagon, I can go on! And he's only EIGHT.
Even if for the wrong reasons, Cartman is smarter than what he seems at first!
He has good plans but he used it for awful stuff remind you of someone?
Stan Marsh
Stanley "Stan" Marsh is a main character of the animated television series South Park. He is voiced by and loosely based on series co-creator Trey Parker. Stan is one of the show's four central characters, along with Kyle Broflovski, Kenny McCormick, and Eric Cartman. Stan actually too smart than Kenny because He mostly generally tender and sensitive.
Kenny McCormick
Kenneth "Kenny" McCormick is a main character in the animated adult television series South Park, along with his friends Stan Marsh, Kyle Broflovski, and Eric Cartman. Kenny may not be the smartest, but he sure is smarter than Stan Marsh.
Craig Tucker
Craig Tucker is a fictional character in the animated television series South Park and is a member of the boys' fourth grade class. Craig's most distinguishing physical feature is his blue chullo hat topped with a yellow puffball. One of his traits is his compulsive tendency to flip people off, usually... read more I think that Craig may not seem smart when you look at him, but he probably has potential or actually is intelligent. It seems like there aren't very many things that interest him, so it's a possibility that he could slack off because of that. Also, Craig is one of the more logical and sensible kids in South Park and seems to want explanations and reasons for people's actions, so it wouldn't surprise me if he was a good student. If he put his mind to something that he really liked or felt passionate about, he would probably be at least one of the smartest kids in class. Also, I agree with the other person: "CRRAIG SMART"
Wendy Testaburger
Winifred "Wendy" Testaburger is a fictional character in the animated television series South Park. She is best known for her on-again, off-again relationship with her boyfriend Stan Marsh, and being more intelligent and mature than most children her age, which is utilized by her activism and feminism... read more
Jimmy Valmer
James "Jimmy" Valmer, is a fictional character from the American animated television series South Park. He is voiced by Trey Parker. He is physically disabled, requiring forearm crutches in order to walk. His disability is confirmed to be cerebral palsy but it is also rumoured to be muscular dystrophy... read more
Butters
Leopold "Butters" Stotch is a fictional character in the animated television series South Park. He is voiced by series co-creator Matt Stone and loosely based on co-producer Eric Stough. He's proven many times he's really smart when he stands for what he believes instead of being naive!
Pip Pirrup
Philip "Pip" Pirrup was a recurring protagonist in the American animated sitcom, South Park. He was an often mistreated, awkward English orphaned exchange 4th Grade student, who was heavily based on the protagonist with a similar name from Charles Dickens' novel, Great Expectations. He was voiced by... read more
Chef
Jerome "Chef" McElroy was a cartoon character on the Comedy Central series South Park who was voiced by soul singer Isaac Hayes.
The Newcomers
? Tolkien Black
? Principal Victoria
The Contenders
Timmy
He's shown many times he's probably the most intelligent of all, but due to him being TIMMY, he can't often showcase it!
Heidi Turner
One of the smartest characters, she is the smartest student in science and is asked to judge the science fair. She's smart enough to know the cancer which is social media and is a very intuitive character.
Big Gay Al
Mr. Garrison
Herbert Garrison is a recurring character in the American animated television series South Park. He is voiced by Trey Parker.
Clyde Donovan
Not very bright at maths but he's smart in other areas he's very clued on
Mr. Mackey
Mr. Mackey is a recurring character in the animated adult television series South Park. He is the guidance counselor at South Park Elementary, best known for saying "m'kay" at the end of most of his sentences. He also serves on the City Council as head of Public Health.
Towelie
Towelie is a recurring character in the animated adult television series South Park. Towelie is a talking towel who was genetically engineered by Tynacorp, in order to allow him to make people as dry as necessary depending on the situation. He is usually seen either appearing out of nowhere to give... read more
Tweek Tweak
Tweek Tweak is a recurring character in the animated adult television series South Park and is a student at South Park Elementary. He drinks lots of coffee, which causes paranoia and jittery muscle spasms. He made his first appearance in the Season Two episode, "Gnomes".