Mummy's boy Harry will attend the private ceremony between Anne Cox and her long-term partner Robin Twist, who helped to raise Harry after his parents split when he was seven.
Anne was Harry's date at this year's Brit Awards and now it's his turn to be there on her big day.
The Mirror reports Anne picked the date to fit in with Harry’s hectic tour schedule - and the rest of the band are also thought to be attending.
Harry was recently snapped on holiday doing his best Athena man impression, adding to his 'family guy' image.
The 19-year-old singer held the band's hairdresser Lou Teasdale's adorable daughter Lux in his arms as he relaxed on his hotel balcony.
One Direction have recently finished the European leg of their Take Me Home Tour but there won't be much time for rest as a new album is set for release by Christmas.