Reese Witherspoon shares throwback photo from her middle school cheerleading days

Reese Witherspoon is throwing it back to her middle school days!

The Big Little Lies star took to Twitter on Thursday to give fans a peek at her teenage life. In the black-and-white snap, Witherspoon is all smiles as she's lifted up for a cheerleading stunt by two other girls. Clad in an adorable uniform repping her school, Harding Academy in Nashville, Tennessee, and rocking a bow in her short, curly hair, Witherspoon is certainly letting her school spirit shine through.

"Say hi to little, cheerleader Reese! #TBT," she captioned the pic, before referencing her upcoming book, Whiskey in a Teacup, which is due out on Sept. 18.

"I loved writing #WhiskeyInATeacup because I had the chance to walk down memory lane," she wrote. "I’m so proud to share with y’all where I come from and some amazing memories from my childhood."

The 42-year-old actress spoke with ET last month about reprising one of her most iconic characters, Elle Woods, in a Legally Blonde sequel. The mother of three confirmed the third movie back in June and, though she couldn't provide any details, Witherspoon teased that the flick will be "so fun."

"I got to go to a meeting the other day and we talked about all the new plot points and all the characters and some returning characters and some new characters," she shared. "...I mean I got so excited just in the meeting. I was like, 'This is going to be good.'"

Legally Blonde 3 is set to premiere on Valentine's Day 2020.