The actress pulled out all the stops for her very first awards show, where the hit Netflix series was nominated for both best drama ensemble and best actress.
Wearing her flame-coloured tresses in glamorous waves, the 19-year-old oozed elegance in a show-stopping gown as she sauntered along the red carpet outside Los Angeles' Shrine Auditorium.
Shannon highlighted her natural skin tone in the off-the-shoulder number, which featured a dramatic, floor-length tulle skirt.
The American star polished off her attire with a lacy nude clutch bag, a slick of red lipstick and statement earrings.
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SAG Awards 2017: Red carpet
Mon, January 30, 2017
Screen Actors Guild Awards 2017. The best and worst dresses from the star-studded red carpet.
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The best and worst dressed from the Screen Actors Guild Awards 2017
You made me feel beautiful!
Sharing a selfie with her 79,000 Twitter followers afterwards, Shannon wrote: "Many thanks to the amazing duo @gregoryarlt and his talented man who did my hair and makeup. You made me feel beautiful."
She was seen posing with her on-screen best friend Natalia Dyer and her fictional boyfriend played by Joe Keery, 24.
Natalia, 20, who plays Nancy Wheeler in the 80s-set show, looked incredible in a red column dress, complete with pink floral embellishment on the neckline.
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The brunette beauty uploaded a photo of herself and Shannon to Instagram, simply captioning it: "Besties."
Stranger Things, which is expected to return with season two later this year, triumphed on the night winning best ensemble, beating the likes of The Crown, Downton Abbey, Game Of Thrones and Westworld.
However, the programme failed to take the best actress gong despite both Millie Bobby Brown and Winona Ryder being nominated. The statuette went to Claire Foy.