The band confirmed that they will play the Peace & Love Festival in Sweden on June 29 and Germany's Melt Festival, which takes place from July 13 to July 15.
Bloc Party revealed in January that they will release a follow-up to 2008's Intimacy later this year.
Frontman Kele Okereke said that the new LP will contain "lean and very tough" material and "sound [unlike] anyone else on the planet".
On the upcoming concerts, guitarist Russell Lissack told fans: "Hard to believe it's been nearly three years since our last show. We're really excited to announce our first festival appearances for this summer, at which we'll be debuting material from our forthcoming new album."
Bloc Party were last year believed to be auditioning replacement singers for Okereke, though reports of his departure were quickly dismissed.
Watch Bloc Party perform 'Mercury' live below: