The X Factor winner was pictured cradling her baby bump on the purple carpet at Thursday night's (15 May) Caudwell Children Butterfly Ball at the Grosnevor Hotel in London.
Sam dressed her blossoming bump in a floor-length black gown, teamed with dark polish and a black clutch bag for an almost gothic glam look.
She attended the glitzy gala with husband Craig, tweeting beforehand: "Looking forward to attending the butterfly ball… such a great cause."
The Butterfly Ball raises money for disabled children and their families.
Last night's event was attended by a string of stars including Peter Andre and Emily MacDonagh, members of the TOWIE cast, Emeli Sandi, the Ecclestone sisters and Holly Valance.
And Steph and Dom Parker – aka the very posh couple from the smash hit Channel 4 show Gogglebox.
Sam snapped a picture with the duo which she posted to Twitter, telling fans: "What a wicked couple @GoggleboxPosh x so nice to meet u."
It's been a pretty great week for Sam who recently learned she's been nominated for three World Music Awards.
The star will battle it out in the 'World's Best Video' and 'World's Best Song' categories for her X Factor winner's track 'Skyscraper', and has been nominated for 'World's Best Entertainer of the Year'.
Not bad for someone who only launched their music career in December and their debut album in March!
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Listen to Sam's 'Skyscraper' below:
Celebrities who announced pregnancies in 2014 in pictures:
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