The band played new song 'Full Stop' during their performance in Cincinnati on Tuesday (June 5).
Rough recordings of the new track have since appeared online, with one being from the band's pre-show soundcheck.
'Full Stop' follows recent new songs 'Identikit' and 'Cut a Hole', which Radiohead debuted at the start of their world tour earlier in the year.
The group will continue to play shows across the summer in support of the latest album The King of Limbs, including a headline set at Spain's Bilbao BBK Live music festival.
Radiohead will then return to the UK on October 6 for a show at Manchester Evening News Arena and two shows at London's O2 Arena on October 8 and 9.
Listen to a fan recording of 'Full Stop' during Radiohead's soundcheck below: