The singer will present the ceremony alongside Gavin & Stacey stars James Corden and Mathew Horne.
Among the performers on the night will be Duffy, Girls Aloud and Kings Of Leon.
"With performances from U2 and Pet Shop Boys already confirmed, the addition of Girls Aloud, Duffy and Kings Of Leon to the bill means we are heading towards a truly special Brits this year," said Ged Doherty, chairman of the Brits committee.
"Added to Kylie, Mathew and James hosting, it's going to be a must-see event. With the nominations launch taking place tomorrow night, the countdown to the 2009 Brits is now truly underway."
Radio 1 DJ Fearne Cotton will unveil the nominees for this year's awards at London's Roundhouse tomorrow.
The Pet Shop Boys have already been announced as the recipients of the Outstanding Contribution To Music award.
The 2009 Brit Awards will be broadcast live on ITV1 on February 18.