, also known as El Barto and Bartman, born April 1, is the tritagonist of the Simpsons franchise. He is Homer and Marge Simpson's eldest child, their only son, and the older brother of Lisa and Maggie.
Bart is a self-proclaimed underachiever who begins each show in detention as part of the opening sequence. His was born on April 1, 1983 (according to Uncensored Family Album) and was conceived on May 21, 1982. He is easily distracted (even, strangely enough, by algebraic equations). His penchant for shocking people began before he was born: Bart "mooned" Dr. Hibbert while he performed a sonogram on Marge, and moments after being born he set fire to Homer's tie. His blood type is the very rare Double O Negative (OO-) ; only he and Mr. Burns are known to have it.
Bart's interests include Krusty the Clown (he is "Krusty Buddy" number 16302), skateboarding, reading comic books (especially Radioactive Man), watching TV (especially The Krusty The Clown Show and The Itchy & Scratchy Show), terrorizing Lisa, playing video games, helping Lisa solve various problems (e.g. reuniting Krusty with his estranged father), and pulling off various pranks (such as mooning unsuspecting people and prank calling Moe Szyslak at his tavern). Bart also sprayed graffiti under the alias 'El Barto', and regularly frequents the Kwik-E-Mart (for bubblegum and Squishees) and The Android's Dungeon.
Bart hinted that his favorite movies are Jaws and the Star Wars trilogy. His best friend is Milhouse Van Houten.
Bart is a polyglot and can speak several languages with varying degrees of fluency. Though he has not demonstrated the ability since his trip to France as an exchange student, he speaks near-perfect French (as a result of drinking wine laced with antifreeze). He also learned Spanish in a matter of hours in preparation for the family's trip to Brazil. Upon learning that Brazilians speak Portuguese and not Spanish, Homer orders his son to forget what he learned, prompting Bart to strike himself over the head until he forgot the language. Bart also speaks Japanese (which he also learned in a couple of hours in prison along with Homer, and is also shown speaking Japanese, Cantonese and Latin. His advanced linguistic skills may be inherited from Homer, who also speaks advanced languages, including penguin. He was also shown to be a skilled drummer. He is a player in the Mighty Pigs Peewee Hockey League Team. He was also quite capable of firing advanced firearms with a frighteningly immense amount of accuracy, as evidenced when, while at Military School as a result of a prank involving bullhorns, he was given a RGB6 Grenade Launcher by the firing range instructor due to his belief that Bart would have most likely known how to operate handguns, and managed to destroy four out of five targets before one of his shots missed and ended up hitting Principal Skinner's car just as he was about to unlock it, to which Bart implied that he deliberately missed the fifth target and was actually aiming for Skinner's car that time. He later displayed a similar proficiency towards weapons when he managed to hijack a tank by stealing the keys, drive it over to the the park, and managed to shoot down a MLB satellite with with surprising accuracy all by himself, although at that point, he was also under the effects of an experimental drug that was supposed to supress Bart's Attention Deficit Disorder.
Bart can also drive vehicles with surprising skill for his age. He has his own driving license, given to him after saving Springfield from a fire, although he has been seen driving before with a fake license at times. He still possesses it, using it to great effect when he stole Principal Skinner's car to get to Jimbo's house.
He is the most misunderstood Simpson, constantly frustrated by the narrow-minded people of Springfield, who judge him merely by his thoughts and actions. Overall, he is a good boy with a few bad ideas (and one or two that are still being reviewed by the Springfield District Attorney) - Basically, Bart is no different from any ordinary 4th grader. When Bart is about to do something mischievous, he does an evil chuckle.
Bart is also a skilled chef. He cooked a three course meal for his parents and made a dessert.
When he was made Hall Monitor, he also had a great degree of skill in enforcing the law and rules. This trait was later exemplified when he, in a similar fashion to a bouncer, removed Homer Simpson from the premises of the La Maison Derrière after he continuously heckled Marge's ventriloquist performance.
Bart is considerably motivated in disrupting the routine at Springfield Elementary, and his pranks are often elaborately complex, but can lead to bad situations. While his actions and speech frequently show considerable mental agility, street-smarts, and understanding. When Bart became a hall monitor for Springfield Elementary, his grades went up, showing that he only struggles because he does not pay any attention, not because he is dumb, in which while he is not as extremely intelligent as his sister Lisa, he is still more intelligent than his father Homer. Later, it is revealed that Bart suffers from Attention Deficit Disorder. He turns out to be musically gifted by becoming an excellent drummer. On the other hand, Bart often seems to have trouble understanding even the simplest concepts, such as the word "irony", what the equator is and that the logo on his globe ("Rand McNally") is not actually a country. It was also once implied that his mischievous behavior may have been a result of Marge accidentally ingesting a droplet of champagne while pregnant with him.
Labeled as an "underachiever" by authority figures, Bart rides an academic rollercoaster, his grades, running the Loop-the-Loop from "F" to "D-" and back again. But he can be ingenious when the chips are down—as long as his ingenuity is never applied to anything school-related. He even learned portions of the Talmud to help reunite his idol, Krusty the Clown, with Krusty's father, Rabbi Hyman Krustofski. Once, after an incident where Bart unleashed a surf wave across the school damaging property (and also saving Ned Flanders who was on fire at the time), he was given an experimental drug for Attention Deficit Disorder called Focusyn (although it took several times to convince him, once causing Homer to wig out when he attempted to eat Focusyn-laced Taffy to convince Bart that it wasn't laced), causing his intellectual potential to reach its maximum, to the extent that he was even capable of tutoring a Navajo boy. Unfortunately, the drug also shortly thereafter drove him paranoid as a side effect, where he started sensing that Major League Baseball is actually spying on them with a satellite, and ended up going beserk when the prospect of being taken off of Focusyn became apparent, sneaking into Fort Fragg and stealing keys to one of its tanks and arrived at Springfield Elementary causing a wake of destruction by driving in the process, and later used its cannon to blow away a MLB satellite, proving his suspicions correct.
Although he gets into endless trouble and is sometimes shallow and selfish, Bart also exhibits many qualities of high integrity. He has, on a few occasions, helped the love life of his school Principal and his teacher, despite the fact he often terrorizes them, and he often befriends outcasts like Milhouse. One great example of his quasi sense of honor is when Bart stands up for Ralph Wiggum at the cost of peer popularity. He was once sent to a juvenile detention center when he played a serious prank involving faux wedding gifts and a fake wedding. He also has legitimate guilt whenever he got either Krabappel or Principal Skinner fired, especially if it was not his intention to do so, like in the former case where he and his classmates plan on getting her laid back by spiking her drink (due to his experience with Homer whenever he's drunk) backfired when she ended up making things dangerous for herself and others and got herself fired, and the latter case where his dog ended up in the ventilation shafts and got trapped along with Willie when he intended to use Santa's Little Helper for show and tell.