The pop star’s album has topped the Billboard 200 chart in the US, selling 1.287 million copies in its first week of release.
The album has sold more copies than last week’s 70 biggest-selling albums in the US combined.
Swift’s third album has outsold her previous fastest-selling record Red, which sold 1.208 million copies in its first week of release in 2012.
It has also has topped the former fastest-selling album of the decade, Eminem’s The Eminem Show in 2002, which sold 1.322 million in its second week at the top of the US album chart.
The 24-year-old has become the first artist to achieve three albums that have sold more than a million copies in the first seven days of release. Her 2010 album Speak Now sold 1.047 copies in its first week.
After just one week on sale, 1989 has become 2014's second largest-selling album in the US, behind only the Frozen soundtrack, which has sold 3.2 million copies this year.
Frozen and 1989 are the only two albums to sell a million copies in 2014, outstripping Coldplay’s Ghost Stories, which held the record for the best first week sales this year, selling 383,000 copies in May.
But the figures released from Billboard, which uses data collected by Nielsen SoundScan, do not include copies of the album sold through a Microsoft promotional tie-in that made the album available for 99 cents.
1989 has in fact been bought by more than 1.287 million people.
The singer’s decision to cut her back catalogue from Spotify appears to have converted into sales for her new album.