The 13 member Disaster Emergency Committee (DEC), including CAFOD, Christian Aid, World Vision and Tearfund, have come together to call for funds to respond to the severe humanitarian needs of those affected.
The DEC said more than half of all new arrivals to Bangladesh are children and one in every ten are pregnant or lactating mothers. The vast majority are living in makeshift shelters made from bamboo and thin plastic.
People are in urgent need of shelter, medical care, water and food.
Onone Chadburn from Christian charity Tearfund told Premier why it's vital to address the immediate humanitarian needs.
She said:"There are only 300,000 people who actually live in Bangladesh. It's already a tightly populated community.
"The Bangladeshi people have been very hospitable in allowing these people to stay.
"We need work closely with the Bangladeshi government to make sure that disease doesn't break out, make sure these people can be in a safe place and things like human trafficking don't begin to happen and to make sure they have a sense of hope and future."
Money raised will support efforts to reach people fleeing Myanmar as well as their host communities in Bangladesh.
The UK Government will match pound for pound the first £3 million donated by the public to the DEC Emergency Appeal.
