The popstar and Voice judge will have her locks cut down to 0.5mm for a 'Big Dare' to raise money for the charity.
© Trevor Leighton
[Jessie J prepares for Red Nose Day]
"Shaving my head for charity is something I've promised to do for a long time and Comic Relief has given me the opportunity to try and raise as much money as possible for good causes by doing it," said the 'Price Tag' popstar.
"I've loved watching Red Nose Day since I was a kid and I'm so excited to join this year's team of celebrity 'fun raisers' and help support the campaign.
"So this Red Nose Day I'll be shaving my head live on the night of TV! I won't deny that I'm nervous but I am also honoured to be part of this year's campaign.