The group will play London's O2 Shepherd's Bush Empire on September 10 in support of their forthcoming album Coexist - which is out the same day - and Cardiff's Coal Exchange on September 11.
The concerts mark the only headline UK dates of their world jaunt, which takes the band across America and throughout Europe.
The xx recently debuted the lead single from their second studio LP 'Angels', which is available for free when pre-ordering the album online.
Singer Romy Madley recently revealed that Coexist is about "lost love", adding: "From exes or the person you're with now.
"A lot of it is still personal, but I've been a bit more inspired by things that have happened to other people and putting myself in their shoes. But they're all love songs and some of them are sadder than others."
Listen to 'Angels' below: