The 'Umbrella' singer looked utterly gorgeous in a dusky pink evening gown as she made her grand entrance to the star-studded gala on Thursday night (11 December).
Rihanna's off-the shoulder gown by designer Zac Posen was teamed with some gorgeous Chopard diamonds… well, it is a Diamond Ball, after all!
The 26-year-old singer launched the black tie fundraiser this year in partnership with The Clara Lionel Foundation, which she found two years ago.
She told fans: "Feel so lucky to have an evening like this, to spend with people with hearts like mine, who want to change and save lives at any cost! There's so much to do, and I can't do it all by myself, so I have to thank all of the supporters of and people who donated to #TheClaraLionelFoundation Looking forward to seeing you later this evening."
The foundation, named in honour of Rihanna's grandparents Clara and Lionel Braithwaite, which aims to improve quality of life for communities around the world in the areas of health, education, arts and culture.
Funds from last night's event will also go to The Clara Braithwate Centre for Oncology and Nuclear Medicine in Barbados, a faculty founded by Rihanna in honour of her late grandmother that provides care for cancer patients on the island.
"One of the greatest benefits of my job was being able to start the Clara Lionel Foundation in honour of my grandparents," said Rihanna.
"There is truly nothing I'm more proud of and we've just gotten started. I'm excited to continue my work and thrilled to be able to host the Diamond Ball – a night that promises to be elegant and inspirational."
US television host Jimmy Kimmel fronted yesterday's event, while guests included Kim Kardashian, Kris Jenner, Ellen Pompeo, Lewis Hamilton and Salma Hayek.
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