Leo DiCaprio is the winner in charitable donations for Hurricane Harvey relief ... he's just cut a check for $1 million.
Leo's foundation gave the money to the United Way Harvey Recovery Fund ... it will be used for both short and long-term relief.
United Way says the entire amount will go to help victims of the epic storm.
This is the first donation to the newly established United Way fund to help victims of the hurricane.
A number of celebs have donated ... notably the Kardashian family gave $500k. Sandra Bullock also gave $1 million to the cause.