The X Factor winner saw off competition from American stars Usher and Madonna to grab the No1 spot with Bleeding Love.
And manager Simon Cowell is over the moon.
'I'm incredibly proud of Leona. What she has achieved in the past year is simply amazing,' he tells the Daily Mail. 'I am very, very happy for her.'
Leona, 22, began a US tour earlier this year to promote her single and debut album Spirit.
She's now hoping the album will hit the No1 spot when it's released in the US on April 8.
Watch Leona perform Bleeding Love at the Brit Awards
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