The birthday girl, meanwhile, wore a slinky gold Saint Laurent slip dress ($4,900) and Sofia, who welcomed her first baby in May, chose a tartan Saint Laurent blouse ($5,556) with black trousers.

"So much fun celebrating with my Virgo Queens," Paris wrote in the caption Paris Hilton had a great time celebrating her friend Nicole Richie! On Sunday, Sept. 22, the socialite, 43, shared a set of glamorous photos from her former The Simple Life costar’s 43rd birthday party on Instagram.

Paris Hilton and Nicole Richie, the iconic duo from the reality TV show "The Simple Life," reunited to celebrate Richie's 43rd birthday in style. The glamorous party was a testament to their enduring friendship and the enduring appeal of their dynamic duo.

Paris Hilton is opening up exclusively to E! News about her new album, 'Infinite Icon,' life with her two kids, Phoenix and London and reuniting with Nicole Richie on the new 'Simple Life' reboot!

Paris Hilton wished Nicole Richie a happy 43rd birthday with a video tribute showing them having fun together on 'The Simple Life' and shooting the new reboot together.

Paris Hilton, 43, gushed about her longtime friendship with Nicole Richie, 42, on Thursday during an appearance on The Tonight Show Starring Jimmy Fallon.

Paris Hilton celebrates longtime friend Nicole Richie's birthday. The 'Simple Life' star took to Instagram to share videos of her sharing highlights and paying homage to her friend on her special day.