Ginerva Molly "Ginny" Weasley is a fictional character in J. K. Rowling's Harry Potter series. Ginny's presence early in the series is minor: she is identified solely as the younger sister of Ron Weasley, Harry Potter's best friend, and harbors a crush on him, while bashful in his presence. Ginny's role is greatly expanded as the storyline progresses, with Rowling developing her character and eventually including her as an active participant in Harry's adventures and the quest to defeat Lord Voldemort, and as Harry's principal love interest.

Ginny is described in the series as being small in stature, having long red hair and bright brown eyes. In the sixth book, Pansy Parkinson states that many boys consider Ginny attractive.

Rowling characterises Ginny as funny, "very warm and compassionate", and "tough, not in an unpleasant way, but... gutsy". During the first books, Ginny is portrayed as shy and quiet in Harry's presence, but according to Ron, she actually "never shuts up". As Ginny's character emerges, she becomes more confident, especially after Hermione's advice to give up on Harry, and begins dating other boys. Readers see evidence that she is assertive and hot-tempered, but also that she is thoughtful and comforting when her sympathies are aroused.

Ginny is one of the few characters who can speak Voldemort's name without fear, as well as being able to address Harry calmly during his worst moods. Rowling drew some comparisons between Lily Evans and Ginny, as she said that both characters were equal in popularity. The author also commented that Ginny and Harry "are real soulmates" and that "They're both very strong and very passionate. That's their connection, and they're remarkable together."

Little is known about Ginny's magical abilities during the first part of the series, but as she joins the D.A., she displays formidable power. As stated by Rowling, Ginny is a gifted witch, and George Weasley claims that "size is no guarantee of power" as he recalls being "on the receiving end of one of her Bat-Bogey Hexes", making this one of her signature spells. Professor Slughorn invites her to join his Slug Club due to her magical prowess, and she held her own in the Battle of Hogwarts despite being only sixteen years old at that time.

Under the influence of Tom Riddle's diary in the second book, Ginny is able to use Parseltongue to open the Chamber of Secrets. Rowling revealed that, as the part of Voldemort's soul inside the diary is destroyed by Harry, Ginny is no longer a Parselmouth nor possessed by Voldemort. In the film adaptation of Order of the Phoenix, her Patronus Charm takes the form of a horse.