The charity said it was sending more health experts to the worst-affected areas as it tries to ease the crisis. A ravaged health care system, devastated infrastructure and near famine -- the results of a bloody civil war that began in March 2015 -- have all contributed to the spread of the disease.
Data analysis shows more than a million acutely malnourished children under the age of 5 -- almost 200,000 of them with severe acute malnutrition -- are living in areas with high levels of infection, Save the Children said.
Malnourished children are at least three times more likely to die if they contract cholera because of their reduced immune systems, the charity said.
The illness, which is spread through contaminated water and causes diarrhea, is easily treated if basic healthcare is in place. But where that is lacking, its symptoms worsen malnutrition even in those who survive the infection, pushing them closer to starvation.
More than 425,000 suspected cases of cholera were reported across Yemen from late April to late July, with 1,900 deaths, according to the World Health Organization. Children under the age of 15 now account for 44% of new cases and 32% of deaths, an increasing proportion.
Tamer Kirolos, Save the Children's country director for Yemen, appealed for international action to tackle the crisis.
"After two years of armed conflict, children are trapped in a brutal cycle of starvation and sickness. And it's simply unacceptable. Our teams are dealing with a horrific scenario of babies and young children who are not only malnourished but also infected with cholera," Kirolos said.
"The tragedy is both malnutrition and cholera are easily treatable if you have access to basic healthcare. But hospitals and clinics have been destroyed, government health workers haven't been paid for almost a year, and the delivery of vital aid is being obstructed."
Al Hali district in Hodeidah has the country's highest number of suspected cholera cases, Save the Children said, with an estimated 31,000 children -- or more than a quarter of children aged under 5 -- in need of treatment for acute malnutrition.
Last week, the head of the UN's relief organization, Stephen O'Brien, warned the UN Security Council that the country's citizens faced a "triple threat"
of "armed conflict, famine, and deadly disease that has already killed, injured, displaced or otherwise affected millions and it will spare no one if it continues unchecked."
Meanwhile, the president of the International Committee of the Red Cross warned that with the rainy season approaching, it expects more than 600,000 cholera cases by the end of the year.
Peter Maurer called on Yemen's warring parties to allow the free flow of aid and let humanitarian workers reach vulnerable populations, in order to ease what he called a "manmade" crisis.
Regional powers are fighting a proxy war in the country of 27 million, located in the southern Arabian peninsula. Saudi Arabia and the United Arab Emirates are supporting the central government in its fight against the Iran-backed Houthi rebels who have toppled the internationally recognized leadership there.
More than two years after it began
, the conflict shows little signs of abating. The Saudi-led coalition and Houthi rebel groups continue to bombard one another, while terrorist groups operate unhindered -- leaving millions of civilians in the crossfire.
Saudi Arabia last week announced a donation of $66.7 million
to UNICEF, the World Health Organization and their partners to fight the disease.
The Yemen conflict has been dubbed the "forgotten war"
because it has been overshadowed by events in Syria and journalists have struggled to get access.