Crystal is the star of films including "When Harry Met Sally ..." and "Analyze This." He participated in a benefit concert for the city a month after the terror attacks. He also has co-hosted eight Comic Relief telethons on HBO to raise money for the homeless.
The foundation has raised more than $350 million privately to build the memorial.
Crystal becomes the 45th member of the board, joining "Analyze This" co-star Robert De Niro.
