Crystal Castles, Lightspeed Champion and Simian Mobile Disco also added
The festival takes place on August 22-24 on the two sites.
The new line-up additions are:
Reading, Friday August 22/Leeds, Saturday August 23
NME/Radio One Stage: Jack Penate, Be Your Own Pet, One Night Only, The Duke Spirit, Blood Red Shoes, Make Model
The Lock Up Stage: Less Than Jake, Pennywise, Goldfinger, The Unseen, H2O, Frank Turner, The Loved Ones, Hexes
Reading, Saturday August 23/Leeds, Sunday August 24
Main Stage: British Sea Power, The Automatic
NME/Radio One Stage: Seasick Steve, The Ting Tings, Mystery Jets, Joe Lean and the Jing Jang Jong, Kids In Glass Houses, Santogold, Bombay Bicycle Club
Lock Up Stage: Gallows, Alkaline Trio, Thrice, Flogging Molly, MXPX, Cancer Bats, Set Your Goals, King Blues, Fucked Up, The Gaslight Anthem, Hi Fi Hand Grenade, Random Hand
Reading, Sunday August 24/Leeds, Friday August 22
The Main Stage: Alexisonfire
NME/Radio One Stage: The Music, Hadouken!, Lightspeed Champion, Cajun Dance Party, Adam Green, Yeasayer, The Metros
Dance Stage: CSS, Digitalism, Simian Mobile Disco, Chromeo, Crystal Castles, Lethal Bizzle, Holy Fuck, The Whip, Robots In Disguise, The Shoes
You can read about the surprise Reading And Leeds Festivals set Lightspeed Champion has lined up in the new edition of NME, available on Wednesday (April 30).