At the time, Witherspoon was just 24 years old, playing what would become one of her most famous roles -- Elle Woods. While many fans can quote the movie line for line, here are four facts not many people know.
1. Witherspoon considered herself to be ditzy in real life. "Every day I get to my mark and I can't remember my lines," she shared with ET during our set visit. "I'm always like, 'Oh no! I'm having a dumb blonde moment. All the peroxide is seeping into my skull.'"
2. Co-star Matthew Davis was starstruck. "I've had a crush on Reese since I was 15," Davis said. "So to actually get a chance to work with her was kind of a treat." Nothing happened between the two, as Witherspoon was married at the time to Ryan Phillippe. "He didn't tell me that!" Witherspoon said when asked if she was aware of Davis' crush. "Well, I'm married and I know he likes my husband a lot, too."
3. Witherspoon and co-star Selma Blair were neighbors. "We lived across the street from each," Witherspoon revealed. "She'd come over. When I'd get locked out of the house, she'd have my key and stuff, so we're really close and it's been great because we get to hang out." For Blair, the feeling was mutual. "She's been a friend since Cruel Intentions," Blair noted. "I would act with her any day."
4. Witherspoon got to keep her outfits. The now 40-year-old actress showed off the wardrobe on Snapchat on Wednesday. "The is Elle's Halloween costume!" she said, rifling through her clothes. "They told her it was a costume party. It wasn't."
In addition to her costumes, Witherspoon has also held on to the ability to bend and snap, as she displayed in an Instagram tutorial, teaching fans how to pull off the act like a pro.
"You pretend you're dropping something and you bend, and then you snap!" Witherspoon said in a video posted on Wednesday. "And that's how it's done."