The "Diamonds" singer showed some serious cleavage in a vintage gold Christian Dior dress at the second annual Diamond Ball in Santa Monica, Calif. on Thursday. She paired her show-stopping silk gown with a sparkling jewel-encrusted necklace.
RiRi hosted the star-studded charity gala for the second year, which supports the Clara Lionel Foundation -- an organization she founded in 2012 in honor of her grandparents, Clara and Lionel Brathwaite -- that works to improve the quality of life for underprivileged communities around the world.
Inside the event, the 27-year-old star talked about her grandmother, who died of cancer in 2012.
"She is definitely here in spirit and she feels delighted to be a part of such a great cause, raising money in her honor, to help, save and change many lives," she told ET.
The brunette beauty also revealed that she's ready to put out some new music. "The album is coming soon!" she teased.
While Rihanna certainly shined on the red carpet, Kylie Jenner also showed off her sexy side at the soiree.
The reality star looked gorgeous in a strapless cream gown with a corseted sweetheart neckline and a dramatic mermaid tail. She completed her look with perfectly-tousled waves and bronze makeup.
She walked the carpet solo, but her boyfriend, Tyga, also was at the party.
Check out all of the stylish stars at the event, including Will and Jada Pinkett-Smith, Emily Ratajkowski and many more!