The Rome-based organization says it helps some 97 million people in about 88 countries each year, and that one in nine people worldwide still do not have enough to eat.
"The need for international solidarity and multilateral cooperation is more conspicuous than ever," Berit Reiss-Andersen, chairwoman of the Norwegian Nobel Committee, told a news conference.
The WFP is a driving force in efforts to prevent the use of hunger as a weapon of war and conflict, with the COVID-19 outbreak further boosting its relevance, she said.
"The coronavirus pandemic has contributed to a strong upsurge in the number of victims of hunger in the world," the Nobel committee said in its citation.
"Until the day we have a medical vaccine, food is the best vaccine against chaos ...
"There is an estimate within the World Food Programme that... there will be 265 million starving people within a year, so of course this is also a call to the international community not to underfund the World Food Programme."
The World Food Programme said this was "a proud moment ... nothing short of a feat."
The prize is worth 10 million Swedish crowns, or around $1.1 million, and will be presented in Oslo on Dec. 10.