Mary Sean Young (born November 20, 1959) is an American actress. She is particularly known for working in science fiction films, although she has performed roles in a variety of genres.
Young's early roles include the independent romance Jane Austen in Manhattan (1980) and the comedy feature Stripes (1981), the latter being a commercial success. Her breakthrough role was that of Rachael in Blade Runner (1982). She then portrayed the character of Chani in the science fiction film Dune (1984), led the neo-noir No Way Out (1987), played Kate in Wall Street (1987), and had starring roles in the comedies Fatal Instinct (1993) and Ace Ventura: Pet Detective (1994).