The full album will be on 15 September – but fans can enjoy the new track until the rest of the music is revealed.
They have said that fans can expect many surprises before Mania is out – and they will be embarking on a Tour
of the US in the autumn.
And the Mania tour will begin in the US on 20 October, with $1 from every ticket sold going to the Fall
Out Boy Fund – which benefits charities throughout Chicago.
Fall Out Boy had been teasing fans on social media, by revealing they had an announcement to make on 28 April.
Various purple-themed hints were dropped on Facebook and Instagram – then bassist and backing vocalist Pete Wentz tweeted that they were going to speed things up.