As 10-million children in the UK go back to school, celebrities are sharing their experiences of being bullied and offering them advice.
Singer Jessie J, former footballer Rio Ferdinand and James McVey from The Vamps are all involved in the campaign.
They'll post photos and tips on social media - and encourage others to do the same.
A recent evaluation showed that 69% of young people believe that Anti-Bullying Ambassadors have decreased the amount of bullying taking place in their schools.
Celebrity supporters were asked what difference having an Anti-Bullying Ambassador in their school would have made to their school experience.
Hit the button below to see what they said.