Susan Pevensie is a fictional character in C. S. Lewis's The Chronicles of Narnia series. Susan is the elder sister and the second eldest Pevensie child. She appears in three of the seven books—as a child in The Lion, the Witch and the Wardrobe and Prince Caspian, and as an adult in The Horse and His Boy. She is also mentioned in The Voyage of the Dawn Treader and The Last Battle. During her reign at the Narnian capital of Cair Paravel, she is known as Queen Susan the Gentle or Queen Susan of the Horn. She was the only Pevensie that survived the train crash on Earth which sent the others to Narnia after The Last Battle.

The Chronicles of Narnia is a series of seven portal fantasy novels by British author C. S. Lewis. Illustrated by Pauline Baynes and originally published between 1950 and 1956, the series is set in the fictional realm of Narnia, a fantasy world of magic, mythical beasts and talking animals. It narrates the adventures of various children who play central roles in the unfolding history of the Narnian world. Except in The Horse and His Boy, the protagonists are all children from the real world who are magically transported to Narnia, where they are sometimes called upon by the lion Aslan to protect Narnia from evil. The books span the entire history of Narnia, from its creation in The Magician's Nephew to its eventual destruction in The Last Battle.