Mary Ann Summers is a fictional Winfield, Kansas farm girl who is a character in the television sitcom Gilligan's Island which ran on the CBS network from 1964 to 1967, and has run more or less continuously since in reruns.
Mary Ann was portrayed by actress Dawn Wells. She was an ingenue and a foil, as well as a friend, to glamorous Hollywood star Ginger Grant, played by Tina Louise. She is apparently regarded with some desire by both the title character Gilligan (Bob Denver) and The Professor (Russell Johnson), but this is never allowed to develop into anything beyond mild flirtation. In addition, her practical domestic skills make her an indispensable member of the group.
She was traveling alone on the "three-hour tour" that was lost at sea, and was in her late teens to early twenties -- an age which she pigeon-holes in the episode "V for Vitamins" when she says, "Women and children first, so I get two votes."