Scott is the ex-wife of Amazon founder Jeff Bezos.
The gift is the largest in the school's history and will significantly boost its endowment.
MORE: Philanthropist MacKenzie Scott donates $42 million to Bay Area nonprofit for low-income students
Scott's team chose Cal State East Bay after a thorough review.
It's also the first school in the Bay Area to benefit from her generosity.
Scott gives regularly to schools -- having vowed to donate the majority of her wealth.