Moss, who wore all black and towering Christian Louboutin stilettos, totted Doherty's acoustic guitar as she arrived at London's Royal Festival Hall.
Back to black: Kate Moss modelled her rock chick look
Pete Doherty delivered a suprise performance of Chim Chim Che-ree
The Babyshambles frontman swapped his usual set of rock tunes for a surprise performance of the Mary Poppins classic Chim Chim Cher-ee.
Moss has a tendency to join Doherty on stage to sing back up vocals, but this time cheered her man on from the crowd.
Number on fan: Moss cheered on Doherty from crowd
The Disney themed performance was for the Forest of No Return, an event which is part of the Meltdown festival.
Doherty is rumoured to be reuniting with Libertines bandmate Carl Barat for a performance at this year's Glastonbury Festival.
A source told the Daily Mirror: "Pete and Carl are still arguing about what songs they're going to perform - but whatever they settle on, it'll be incredible."
Doherty is set to perform at Glastonbury, where he is rumoured to be reuniting with Libertines band mate Carl Barat