Schools and workplaces will be doing something funny for money today — as well as bake sales and wearing those classic red noses!
In the thirty years it has been fundraising, Comic Relief and Sports Relief has raised more than £950 million, supporting people in need in the UK and around the world.
Are you joining the fun today? We want your pictures!
Email your Comic Relief photos to Samantha.Robinson@trinitymirror.com or share them with us on Facebook and Twitter.
Please include your name and the names of people photographed, where you are and what you're up to!
Whether you're dressing in red for the day, sitting in a bath of baked beans, enjoying a fancy dress party or selling Red Nose Day themed cakes and buns, we want to see what you're doing to raise money.
Tonight's Comic Relief programme will include performances from Rowan Atkinson as Mr Bean, Dermot O'Leary's 24-hour dance-a-thon and Dawn French will return as the Vicar of Dibley.
Watch Little Britain's carer Lou taking care of important patient Stephen Hawking, and enjoy musical performances from Ella Henderson and Sam Smith.
Comic Relief kicks off at 7pm on BBC One.