The success of the record, her seventh studio LP, brings her total US album sales to over 32 million.
Femme Fatale has also achieved platinum status in Canada and is gold-certified in the UK, France, Mexico, Czech Republic, Brazil, Korea and Singapore.
She remains the only female artist to have six albums debut at No.1 on the Billboard 200 albums chart.
Spears is currently rehearsing for her 26-date 'Femme Fatale' US tour, which also features rapper Nicki Minaj.
Watch the video for Britney Spears - 'Till The World Ends' below: