Sharapova made the announcement at a news conference at United Nations headquarters in New York, where she was also made a UN goodwill ambassador.
Sharapova, whose family lived not far from Chornobyl at the time of the accident, said she hoped the money would help rebuild schools, hospitals, and sports facilities near the site of the accident.
The explosion at the Chornobyl nuclear power plant in Ukraine in April 1986 was the world's worst civilian nuclear accident.
Its long-term health effects are still unclear, but the UN has predicted it will cause up to 9,000 extra deaths from cancer in the most affected areas.