Sales of individual music tracks - which count towards the top 40 singles chart - have risen by almost a third.
A record-breaking 152 million singles were sold in 2009, and 98% of those were downloads.
This is the second year in a row that sales of singles have risen - 2008 was also a record-setting 12 months.
Music industry experts reckon the closure of big shops that used to sell singles, like Woolworths, mean more people are getting their tunes online.
The number of albums downloaded digitally also rose, with 16.1 million albums sold online. That's almost six million more than the year before.
The rise of online music sales has been good news for artists like Lady Gaga, whose song Poker Face was the best-selling single of 2009.