The money for the Global Polio Eradication Initiative (GPEI) should mean an extra 45m children can be vaccinated.
Over the last 20 years, polio cases have been cut by 99%, and the condition is close to being eradicated. It is still endemic in Afghanistan, India, Nigeria and Pakistan. And it is present in over a dozen countries altogether.
The UK currently donates £20m each year to GPEI, which is led by the World Health Organization (WHO).
The extra money will be given on the understanding that routine immunisation is strengthened in the countries affected.
The UK government has also called for each dollar of its funding to be matched by $5 from other donors.
The Bill & Melinda Gates Foundation is to donate an extra $102m (£64.3m) to the GPEI.
The GPEI is a public-private partnership, spearheaded by the WHO. It is funded by the US, UK and Indian governments, Rotary International and the Bill and Melinda Gates Foundation.