Reese Witherspoon Gets Private Taylor Swift Concert For 40th Birthday [PHOTOS]

Resse Witherspoon celebrated her 40th birthday in style over the weekend thanks to some of her famous friends. The actress rang in her 40s in a star-studded bash Saturday night that even included a private concert from Taylor Swift.

For the celebration, Witherspoon rented out the Warwick in Los Angeles that was attended by Kate Hudson, Jennifer Aniston, Justin Theroux, Courteney Cox, Matthew McConaughey, Robert Downey Jr., Isla Fisher, Conan O'Brien, Chris Martin, Chelsea Handler, Tobey Maguire and more. The party kicked off at 7:30 p.m., and the actress arrived with an entourage of three black SUVs that carried her family, including husband Jim Toth and her mother.

"Reese was smiling and seemed excited about her party. She wore a sparkly cocktail dress and looked amazing," a source said.

Later on in the night, the party turned into a mini-concert with Swift and Keith Urban both taking the stage. The 26-year-old singer performed an acoustic version of "Shake It Off" while Urban played "Sweet Home Alabama." During Urban's rendition of the classic song, the actress, who starred in the film "Sweet Home Alabama," jumped onstage with the country singer to help perform the tune.

Hudson took to her social media after the party and posted a couple of pictures from the party to her Instagram account.

"When you take a s--t load of pictures and you still don't have it perfect so you go for the ole collage post..." Hudson wrote. "Happy Birthday gorgeous girl @reesewitherspoon !!! Love you #TequillaFirst #PostingLater #SaturdayNight #ImSoExcitedToGetIntoBedIDontEvenKnowWhatToDoWithMyself #NotWashingMyFace #GoodNight."

Hudson, who was also celebrating her birthday, and Witherspoon both let loose at the party and tore up the dance floor together. "[Hudson] and Reese were tearing up the dance floor having the best time," the insider said. "They were posing for pictures all night long and Erin Foster was interviewing them asking them funny questions."

"It was a great party. When Reese left at 2 a.m., she was in the best mood," the source added. "You could tell that she had the best time celebrating her birthday."