Marge is the well-meaning and extremely patient mother of the Simpson family. With her husband Homer, she has three children: Bart, Lisa and Maggie. Marge is the moralistic force in her family and often provides a grounding voice in the midst of her family's antics by trying to maintain order in the Simpson household. She is often portrayed as a stereotypical television mother and is often included on lists of top "TV moms". She has appeared in other media relating to The Simpsons including video games, The Simpsons Movie, The Simpsons Ride, commercials, and comic books and inspired an entire line of merchandise.

Lisa Simpson is 8 years old and is the middle of the Simpson children. She was born on September 28,1981. She loves jazz music, playing the saxophone her father bought her, playing with Malibu Stacy dolls, and defending the environment and animal rights. After an encounter at a local petting zoo she became a vegetarian. Although still a child - Lisa displays wisdom and thoughts beyond her years - her maturity level surpasses her classmates and many adults, including her father. Her IQ is the highest in her family - she enjoys reading and studying and because of this she often finds herself alone and friendless. Periodically Lisa will make a friend but it never seems to last too long, as usually by the next episode Lisa is by herself again. Her brother Bart's best friend Milhouse has a crush on Lisa - but she doesn't have any interest in him.

Bartholomew "Bart" JoJo Simpson (b. April 1,1979) is a ten-year-old rebellious boy who is anti-authority Bart lives in an American community called Springfield. He is the son of Homer and Marge Simpson and brother of Lisa and Maggie Simpson. He attends Springfield Elementary School. Other family members are his Grandparents Abraham and Mona Simpson and Clancy Bouvier (deceased) and Jacqueline Bouvier. His best friend is Milhouse Vanhouten and his school enemy is Nelson Muntz. Catchphrases "Eat my shorts", "¡Ay, caramba!", and "Don't have a cow, man!"

Krusty the Clown, born Herschel Shmoikel Pinchas Yerucham Krustofski, was born in the Lower East Side of Springfield and is the son of Hyman Krustofski. Very little is known about his mother, aside from her name being Rachel and that she died when Krusty was around thirteen. Hyman strongly opposed Krusty's wish to become a clown and make people laugh, believing that it would distract him from his religion, wanting the boy to go to yeshiva instead. However, Krusty performed slapstick comedy behind his father's back. One day, he was performing at a rabbis' convention when one joking rabbi squirted seltzer on him, washing off his clown makeup. When Rabbi Krustofski found out, he disowned his son, and did not speak to him for 25 years. Krusty was later reconciled with his father with the assistance of Bart and Lisa Simpson. It was later revealed that Krusty did not have a Bar Mitzvah service, because Hyman feared he would violate the sanctity of the rites by "acting up." Krusty had two adult Bar Mitzvah ceremonies: a Hollywood gala which Krusty uses to stage a comeback after his show is cancelled, then a simple ceremony intended to reconnect with his father. After leaving the Lower East Side of Springfield, Krusty started his show biz career as a street mime in Tupelo, Mississippi. Krusty later discovered that he has a daughter named Sophie. He had met Sophie's mother when she served as a soldier in the Gulf War and he was entertaining the troops. After spending the night together, he prevented her from assassinating Saddam Hussein to protect his Saddam-themed comedy act. After that she started hating clowns, and kept their daughter a secret from Krusty.