To perform her newest single "Your Song", at the awards show, which took place in London, she rocked a black sports bra and sheer tights under an oversized black blazer.
The 18-year-old musician is nominated for five awards at the show - Best Canadian Act, Best Song for "There's Nothing Holdin' Me Back", Best Artist, Best Pop, and Best Fans.
Sheeran was among a number of British winners on the night as he capped a whirlwind 12 months - which has seen him release his acclaimed third album, Divide, and headline Glastonbury - with a win the best live category. Dua Lipa scooped the best new artist accolade.
The ceremony was hosted by Rita Ora, who at one point sported a dressing gown on stage. Other highlights included Travis Scott rapping "Butterfly Effect" on top of an animatronic bird, United Kingdom hip-hop star Stormzy's "Big for Your Boots", and a new U2 song - "Get Out Of Your Own Way" - performed by Bono and company from Trafalgar Square.
Jared Leto's band Thirty Seconds to Mars won best alternative act, and Leto used his time on stage to discuss immigration, saying: "We are Americans, a land of immigrants, and we just want to say we welcome you with open arms and open hearts and we love you". "Congratulations to all the winners and thank you to the wonderful crowd!"
Eminem's new single 'Walk On Water' featuring Beyonce is getting all kinds of reactions from the audience.