Tuesday marks a major milestone for Reese Witherspoon [1], as it will be her 40th birthday. On Saturday, the actress got a head start on the celebration with a night out on the town with a huge group of her famous pals, including Kate Hudson [2], Jennifer Aniston [3], Justin Theroux, Chris Martin [4], Courteney Cox [5], Sarah Paulson, Matthew McConaughey [6], Isla Fisher [7], and Tobey Maguire [8]. In addition to Reese's friends stepping out, she also got a private concert from Taylor Swift [9] and hit the stage with Keith Urban [10]!

Fortunately, both Reese and Kate took to social media to document their night. The mom of Ava [11], Deacon, and Tennessee shared a few fun pictures on Snapchat and Instagram, including a gorgeous birthday snap of herself in a sparkly minidress [12] with a caption that read, "Happy Saturday y'all!! #BirthdayWeekend." Kate, on the other hand, opted for a festive photo collage [13] and wrote, "When you take a sh*t load of pictures and you still don't have it perfect so you go for the ole collage post....Happy Birthday gorgeous girl @reesewitherspoon !!! Love you #TequillaFirst #PostingLater #SaturdayNight #ImSoExcitedToGetIntoBedIDontEvenKnowWhatToDoWithMyself #NotWashingMyFace #GoodNight." Keep reading to see more of the girls' night out, and then check out even more celebrities who are turning 40 this year [14].