Last year the UK Government recorded 300 suspected cases of forced marriages.
There are no official figures for the number of children forced to marry as many are too afraid or embarrassed to speak to the police about their situation.
Around 200 young people were rescued last year from marriages but it's thought the actual figure is much bigger.
Where does it happen?
They happen all over the world including the UK. However, most cases involve girls and young women in Pakistan and Bangladesh.
There have been cases in, Africa, China, Japan and the United States.
But it's not just girls that are affected. Boys are also forced into marriage.