Margaret Evelyn "Maggie" Simpson is the youngest child of Marge and Homer and the adorable and beautiful baby sister to Bart and Lisa. She is often seen sucking on her pacifier, and, when she walks, she trips over her clothing and falls on her face. Because she cannot talk, Maggie is the least seen and heard in the Simpson family.
When Marge became pregnant with Lisa, she and Homer bought their first home. Eight years later, Homer felt financially secure enough to quit his job at power plant and take his dream job at Barney's Bowlarama. Soon after, Marge became pregnant with Maggie, and unable to support his family, Homer reapplied for his job at the power plant. Homer fell into a deep depression but when he held Maggie for the first time after she was born he loved her at first sight. He keeps all of Maggie's baby photos in his office to cheer him up at his workplace.
Maggie is the most mature member in the family. However, she keeps her intelligence a secret in order to be babied. This is first revealed when Marge gives her a new pacifier, and when Marge isn't looking she smokes it like a cigarette.
Like average babies, Maggie is impressionable and easily influenced by what she sees around her. She once hit her father on the head with a mallet, shot a suction dart at his picture and brandished a pencil in imitation of Itchy and Scratchy. Despite her age, Maggie is a formidable markswoman and she shot the fingers off of a group of mobsters in rapid succession with a rifle. She was behind the attempted murder of Mr. Burns and she fought Gerald during the St. Patrick day riot, her representing Ireland and Gerald Northern Ireland. When the family's house was being raided by an angry mob, she was able to smash her baby bottle and use it as a makeshift weapon, and she knocked out Russ Cargill, the evil head of the EPA with a rock when he was about to shoot Homer and Bart with a shotgun.
Maggie is often frightened of her father's attempts to bond with her, even though she does love him. Instead, Maggie shows a much stronger attraction to her mother instead, possibly because Marge is always at home with her whilst Homer is mostly at work or at Moe's.
She is keenly aware of her surroundings, and can usually be seen imitating the flow of action around her. Like Bart, Lisa and Homer, she is not fond of spending time with her aunts Patty and Selma. It is also known that she dislikes Gerald, the one eyebrowed baby very much, despite apparently marrying him in one Simpsons Comics.
Maggie bears a strong resemblance to Lisa, suggesting that Maggie will look very much like her sister when she reaches eight-years-old.
Maggie's first word is "Daddy", something neither Bart or Lisa would call him when they were babies. On another occasion, Maggie's speaks the word "Ya"; a Norwegian word. She has also said "Dadily Doodily" when she was in the care of Ned Flanders.
She has a large resemblance to Lisa having her hair and hair style. she wears a light blue bow and a light blue onesie
Maggie is a violent child, especially for her age and despite her cuteness and beauty. Maggie once had a violent relationship with Homer after watching Itchy and Scratcy. She had hit him over the head with a hammer and later attempted to stab him with a pencil.
When Mr Burns decided to cover up the sun, he was shot by Maggie. Maggie shot him while Mr Burns was trying to steal a candy from her. After figuring this out, it eliminated the witness of Homer.
In the Simpsons Movie, when the mob was attacking the Simpsons, Krusty told his monkey, Mr. Teeny, to take out the baby, referring to Maggie. Maggie than broke her baby bottle making rigid spikes of glass, showing that she was ready to take him on.