The 33-year-old American actress will give the money to the World Food Program, a U.N. body that delivers millions of tons of food aid to more than 70 million people in about 80 countries, she said on "The Oprah Winfrey Show."
"I'm able to make this incredible donation — this has changed my life," said Barrymore, who serves as a WFP ambassador against hunger. "But I encourage everyone to give."
Later, she told The Associated Press that the US$1 million (€660,000) was "by far" the largest donation she has ever made.
"But nothing has ever felt so good," she said.