The singer is only the 16th person to have shifted more than a million albums in a week since Nielsen SoundScan started tracking sales in 1991, reports the BBC. She now holds the highest number of record sales since 50 Cent's The Massacre reached number one.
Swift's album has the second-largest sales week of any country album since 1991, coming second to Garth Brooks' 1998 effort Double Live. According to US music website Billboard, industry experts had predicted Swift''s record would sell up to 900,000 copies.
'Speak Now" is her second number one album, after 'Fearless" topped the chart in 2008.