I Dreamed A Dream broke the record for the biggest first-week sales for a UK debut album last week when it entered the chart at number one.
The Britain's Got Talent runner-up has now sold over 700,000 copies in two weeks, making the record one of the biggest-selling albums of the year.
It is beaten only by Lady GaGa's The Fame, which has spent 47 weeks in the chart, and Kings of Leon's Only By The Night, which has been in the chart for 63 weeks.
Martin Talbot, managing director of the Official Charts Company, said: "Susan Boyle's debut was historic and we expect 'the Susan Boyle effect' to be felt in the charts for a long time to come yet."
Elsewhere in the chart, Take That's live album The Greatest Day - The Circus Live reached number three. It is the fastest-selling live album since 1994, shifting over 123,000 copies in its first week.
Meanwhile, Westlife earnt their twelfth top ten album with Where We Are, which charted at number two.
The top ten albums in full (click where possible for our reviews):
1. (1) Susan Boyle: 'I Dreamed A Dream'
2. (-) Westlife: 'Where We Are'
3. (-) Take That: 'The Greatest Day - The Circus Live'
4. (2) JLS: 'JLS'
5. (3) Black Eyed Peas: 'The E.N.D.'
6. (6) Michael Bublé: 'Crazy Love'
7. (4) Queen: 'Absolute Greatest'
8. (8) Snow Patrol: 'Up To Now'
9. (5) Leona Lewis: 'Echo'
10. (9) Robbie Williams: 'Reality Killed The Video Star'
Source: Official Charts Company
> Click here for this week's top ten singles