Christmas Jumper Day is celebrated worldwide, especially in the United Kingdom and Ireland, every December 11. This fundraising event, organized by the charity Save the Children, invites people to wear Christmas jumpers and donate at least £2 to help vulnerable children. Since it began in 2012, the campaign has raised more than £40 million. Participants are encouraged to wear jumpers they already have, decorate plain ones, or choose secondhand options to promote sustainability. While many schools and workplaces join as groups, anyone can take part individually without needing to register. The day is a fun and meaningful way to support Save the Children’s efforts to improve children’s health, education, and protection around the world.