Alba, 28, made headlines recently when she plastered posters of great white sharks around Oklahoma City -- where she had been shooting a movie -- to raise awareness about the species' dwindling numbers.
The "Fantastic Four" actress publicly apologized for her actions and police said none of the owners of the property Alba papered wished to press vandalism charges against her.
"We're very pleased she made a contribution," United Way spokeswoman Erin Brewer told the Oklahoman newspaper.
E! News said the amount of the donation was not disclosed.