The Ginny Weasley costume is a popular costume based on a female character from the Harry Potter series.
The costume consists of a girl's school uniform with a red and yellow striped tie (the colors of Gryffindor house to which Ginny Weasley belongs). A robe can also be worn with the costume and the wearer can carry a wand as a prop. The character of Ginny Weasley has long red hair, therefore if the costume wearer's hair does not match that of Ginny Weasley, he or she may well choose to wear a wig.
Ginny Weasley is the youngest of the Weasley children and a member of Dumbledore's Army. She had a crush on Harry Potter, although she eventually gave up on him and moved on. She is one of five members of Dumbledore's Army who accompanied Harry in his attempt to rescue Sirius Black from the Department of Mysteries. She eventually ends up in a relationship with Harry and becomes his wife, bearing him three children.