Elizabeth Brooke "Lizzie" McGuire is the titular protagonist of the show Lizzie McGuire. She is portrayed as a caring, rational, and cooperative person, although her animated alter-ego displays her true feelings from time to time.
As the show progresses, Lizzie undergoes various "image" changes, including becoming rebellious, disrespectful, and rude in the episode, "Bad Girl McGuire". She constantly gets into arguments with her younger brother, Matt McGuire, but is well-aware of what is right and wrong.
Lizzie is a sweet, beautiful, honest teenage girl, who always knows when to do the right thing. She sticks up for her friends, but sometimes she needs reminding to as shown in some episodes. She is very kind and is even nice to her enemies, such as Kate Sanders. All Lizzie wants to do is get by life one step at a time. She is always trying to impress her crushes, such as Ethan Craft. She often has the urge to try to become part of the "popular crowd", as exemplified by her "arch-enemy" (and former friend), Kate. Sometimes when she does something that gets her temporarily popular she decides that this sort of life is not for her and gives it up, as shown during the time she becomes a teen model and the time she dated a celebrity. Lizzie is allergic to strawberries and oyster sauce.
Lizzie once said that she hates Matt so much that she believed that she is allergic to "him", as a running gag, Lizzie shows she seems to have a crush on her best friend Gordo, she even kissed him twice. It is seen at the end of the movie that they had become a couple.
Miranda Sanchez is Lizzie's other best friend. Lizzie has known her for a long time and will do absolutely anything for her.
Kate used to be Lizzie and Miranda's best friend until she became popular. They renewed the friendship in the movie.