|Family & Friends|
|First appearance:||Pool Party|
|Last appearance:||Magic Train|
Kate Sanders is the primary antagonist.
She's the most popular girl at Lizzie's school, and also the captain of the school cheerleading squad. Kate was originally Lizzie and Miranda's best friend, but then she became popular because she got a bra after summer camp. As a result of her newfound popularity, Kate becomes their (mainly Lizzie's) enemy. Kate enjoys trying to make their lives miserable, but they always outsmart Kate and come out on top. During Season 1 Kate's last name was pronounced Saunders, but in Season 2 the pronunciation of Kate's last name was changed to Sanders.
Despite normally being mean to Lizzie and her friends, some episodes have shown her friendlier side, implying that she doesn't really hate them and that she also doesn't like being mean to people, but thinks she has to act mean since she's popular. And while Kate was mean to Lizzie and her friends in the series, she helps them out and becomes their friend again in The Lizzie McGuire Movie.
In the episode I've Got Rhythmic, it's shown that Kate isn't very good at rhythmic gymnastics, and gets jealous when she sees that Lizzie is extremely good at it (although Lizzie later admits to her parents that she hates rhythmic gymnastics and the only thing she likes about it is that she's good at it). It seems rather ironic that Kate would be bad at something like rhythmic gymnastics but yet she's on her school cheerleading squad, since gymnastics in general is a huge part of cheerleading.
Mr. and Mrs. Sanders are never seen, but are mentioned numerous times. One of the episodes Kate's mother is mentioned in is the Season 2 episode "Party Over Here," where Kate was having a big birthday party and her mom made her invite all of her classmates (although Kate later told Lizzie that she felt Kate should have a grown-up party, and then left town). In that episode, it's implied that Kate might be lonely, because during a phone call between her and her mother, Kate's mother said that she wouldn't be home in time for Kate's birthday.
Kate's cousin, presumably from her father's side of the family, who was seen in Party Over Here as the chaperone at Kate's birthday party (although Amy didn't even realize that it was Kate's birthday). The two are shown to have a rocky relationship, and despite the fact that Amy's technically an adult at the age of eighteen, Kate's actually much nicer and more mature and responsible than Amy is.
Kate's new best friend after Kate stopped being friends with Lizzie, Miranda and Gordo. Even though Kate's usually the leader/more dominant of the two, Claire, at times, can be a lot meaner than Kate is, such as in The Rise and Fall of the Kate Empire.
Claire often pressures Kate to not renew her friendship with Lizzie and Miranda. One reason for that could be that Claire might be jealous of the friendship Kate once had with them and that somebody might end up replacing her as Kate's best friend.
Kate and Claire are members of their school cheerleading squad, with Kate as the captain and Claire as her second-in-command, and both girls seem to have a decent relationship with their fellow cheerleaders. Despite the fact that Kate and Claire are two of the most popular girls in school, they don't seem to have very many friends outside of each other and their fellow cheerleaders.
- Kate's favorite color is purple.
- Kate got held back when she was in kindergarten, so she's actually a year older than most of the other kids in her grade.
- Kate is allergic to temporary tattoo ink.
- Kate was played by Ashlie Brillault, who originally auditioned for the role of Lizzie McGuire, but ended up with Kate's role.
- Kate Sanders is very similar to Lexi Reed from ANT Farm and Nina Harper from Braceface (who she probably shares the most similarities with).
- Kate has a teddy bear named Mr. Stuart Wugglesby.