The 28-year-old actress, who's nominated for Best Actress in a Musical or Comedy for her role in La La Land, brought her younger brother, Spencer Stone, as her date to the 74th Annual Golden Globes at the Beverly Hilton Hotel in Los Angeles on Sunday.
Spencer, who is best known for his work in Divergent, V/H/S/2 and Sharknado, appeared in good spirits, joining his big sis throughout various on-camera interviews.
Prior to hitting the red carpet, a few of Stone's beauty secrets were revealed thanks to her makeup artist, Rachel Goodwin, who posted this hilarious Instagram photo of the actress wearing a KNC Beauty Lip Mask.
Once on the red carpet, Stone turned heads in a custom Valentino Haute Couture gown designed exclusively for the actress by creative director Pierpaolo Piccioli.
Catch all of ET's live coverage right here on ETonline.com, on Twitter (@etnow) and Instagram (@entertainmenttonight). Also be sure to check out ET's official Facebook page at 8:30 p.m. PT for live updates on the night's most memorable moments ahead of our full post-show coverage airing Monday on Entertainment Tonight.