Which Narnia character is the first Pevensie child to enter the wardrobe?

Lucy Pevensie is the first Pevensie child to enter the wardrobe in The Lion, the Witch and the Wardrobe.

While exploring the old house during a game of hide-and-seek, Lucy steps into a wardrobe and discovers that it leads to Narnia. She meets the faun Mr. Tumnus, who explains that the land is under the rule of the White Witch. Lucy returns to the ordinary world and tells her siblings, but they initially doubt her story.

Edmund later enters the wardrobe and encounters the White Witch, while Peter and Susan enter after the children investigate together. Lucy’s first discovery therefore begins the siblings’ involvement in Narnia and drives the early conflict of the novel.

Lucy appears throughout the Narnia series and is often associated with faith, courage, and perceptiveness. She is the youngest of the four Pevensie children in the first book. The answer is Lucy Pevensie, not Lucy’s friend or one of the book’s magical creatures.