CAFOD, Christian Aid, Tearfund and World Vision are among 13 charities part of the Disasters Emergency Committee (DEC), which come together to launch urgent appeals when major wars or natural disasters strike nations.
The DEC says Yemen is at "breaking point" following 20 months of conflict and seven million people there do not know where their next meal will come from.
Two million children are also currently malnourished in Yemen.
Yemen imports virtually all of its food and fuel, but bombing and blockades have significantly reduced its access to supplies.
Its launch comes after Foreign Secretary Boris Johnson said he had "deep concern" about the suffering of Yemenis but backed the Saudi Arabia-led military intervention in the country.
Saudi Arabia is supporting the internationally-recognised government of Yemen against Iran-backed Houthi rebels.
Asking an urgent question in the Commons on Monday Yemeni-born Labour MP Keith Vaz said the Government "must speak with one voice and with one aim" for Yemen.
International Development Secretary Priti Patel said Yemen "faces a humanitarian crisis that the international community cannot ignore" and ministers will match donations from the UK public up to £5 million.
She said: "By matching pound for pound public donations to the DEC appeal, we will double the difference British people can make to the lives of undernourished children with clean water, lifesaving food and medical treatment."