Biffy Clyro will headline Reading and Leeds festivals this summer, while System Of A Down, Bring Me The Horizon, Jake Bugg and Foals have also been added to the line up.
The Black Chandelier rockers - who reached number one in the UK album charts with their new record Opposites on Sunday (02.02.13) - will headline the parallel rock events held in England this August.
Frontman Simon Neil told the NME: "Reading always felt like such an exotic festival. Even though it's been around since the 70s, it just really seemed to come alive in the 90s.
"I think that's when it became the cultural moment that it is now, and the fixture that it is in the calendar. It's just f***ing bizarre. I still can't get my head round it."
Rapper Eminem has already been announced as headliner, with a third to follow.
Also confirmed for the festivals are System Of A Down, Bring Me The Horizon, Jake Bugg and Foals.
Previously confirmed for the Reading and Leeds bill are Alt-J, Sub Focus and Deftones.
Fall Out Boy will also appear on the main stage, after announcing yesterday (04.02.13) they were back together after a three year hiatus.
The band said: "When we were kids the only thing that got us through most days was music. It's why we started Fall Out Boy in the first place.
"This isn't a reunion because we never broke up. We needed to plug back in and make some music that matters to us.
"The future of Fall Out Boy starts now. Save Rock And Roll."
Reading and Leeds festivals will take place on 23 and 25 August. Tickets available here.