Lady Gaga reached number one with her debut single in January
Lady Gaga's Poker Face is the most downloaded song since the download chart began five years ago, the Official UK Charts Company says.
The single notched up 779,000 sales on downloads alone to top the chart, and her first UK release Just Dance is the third most downloaded with 700,000.
Kings of Leon featured at numbers two and four with their hits Sex on Fire and Use Somebody.
La Roux's In For The Kill came in at number five.
This was the most recent release in the top 10, first charting in March.
Lady Gaga, whose debut album The Fame was released this year, said: "I am honoured to be the songwriter and performer behind the number one and number three all-time most downloaded songs in history in the UK."
The fact that the top five tracks were all released within the past 12 months indicates how important download sales now are to the music industry - digital sales now account for around 98% of the singles market.
ALL-TIME TOP 10 OFFICIAL UK DOWNLOADS
1. Poker Face - Lady Gaga
2. Sex On Fire - Kings Of Leon
3. Just Dance - Lady Gaga
4. Use Somebody - Kings Of Leon
5. In For The Kill - La Roux
6. Run - Leona Lewis
7. Hallelujah - Alexandra Burke
8. Bleeding Love - Leona Lewis
9. Chasing Cars - Snow Patrol
10. Rockstar - Nickelback
Source: Official Charts Company
The chart reflects the growth of downloads over the past two years in particular. The Top 100 features 46 entries from 2008 and 21 from 2009 so far.
The Official Download Chart was launched in September 2004 to reflect the most popular tracks within the legitimate download business.
Meanwhile, in the official UK singles chart, Jay-Z's collaboration with Rihanna and Kanye West - Run This Town - went straight in at number one.
Sugababes' track Get Sexy made another new entry at two, while Kings of Leon's Sex on Fire jumped to six from 33 helped by an X Factor auditionee performing it last week.
In the album chart, Arctic Monkeys held on to the top spot for a second week with Humbug, holding off an assault from Dame Vera Lynn.
After entering the album chart at number 20 last week, Dame Vera had been hoping to gain the accolade of being the oldest living artist to score a number one album, but was held off the top spot at number two with her collection of best-loved recordings.
However, a surge in sales helped her chart higher than rivals David Guetta, Kings of Leon and the Black Eyed Peas who occupied the rest of the top five.