The campaign, created by Exposure, will tour UK festivals this summer and ask festival-goers to leave their thumbprints as a show of support and to push governments to act.
A 9m high, 5m wide 'lantern'-style installation will appear at events including V Festival, Bestival and the Bristol Balloon Fiesta, with the aim of collecting 100,000 thumbprints.
The campaign aims to raise awareness of and support calls for four key policies that will help to eradicate child mortality - for clean water, healthcare, to end hunger and prevent disasters.
Support for the initiative will be presented to governments to force them to take action to stop children dying.