Harry, 18, opens the video by saying to the camera: "One third of children in sub-Saharan Africa are malnourished."
Zayn, 20, adds: "Big corporations avoid paying millions to Africa every day. If we stop this, all of Africa could have enough food to eat."
'Pirates of the Caribbean' actor Orlando Bloom also appears in the clip, asking: "The world produces enough food for everyone. Why are one billion people going hungry?"
Actor David Harewood, who plays CIA agent David Estes in the hit drama 'Homeland', continues: "When there is enough food to feed everyone, why are 870 million going hungry?"
Other famous names who appear in the video include Microsoft chief Bill Gates, 'Love Actually' actor Bill Nighy and South African social rights campaigner Archbishop Desmond Tutu.
Sarah Jacobs from Save the Children - who are one of the many charities pushing the campaign towards ending world hunger - hopes the famous names will gain them the attention and action they are seeking.
She said: "The last time a campaign came together with this many people involved was Make Poverty History.
"It's a major crisis that we need to tackle. We've made amazing progress in the last few years, but the issue of poverty has been sidelined.
"We need to make sure that promises which have been made by governments about life saving are carried through. World leaders can't ignore us if we come together in our masses."
The campaign - which is also backed by charities including Oxfam, Action Aid, Christian Aid and Unicef - launched in London on Wednesday night.