Which Narnia book introduces the wardrobe that leads to Narnia?

The Narnia book that introduces the wardrobe leading to Narnia is The Lion, the Witch and the Wardrobe.

Published in 1950, the novel follows four siblings—Peter, Susan, Edmund, and Lucy Pevensie—after Lucy discovers a passage through a wardrobe in a country house. Beyond it lies Narnia, a magical land suffering under the rule of the White Witch.

The story introduces Aslan, the great lion who serves as Narnia’s central heroic and spiritual figure. It also establishes the series’ blend of talking animals, mythological creatures, adventure, and Christian symbolism. The book was the first Narnia novel Lewis wrote and the first published in the series.

Some reading orders place The Magician’s Nephew first because it tells an earlier story in Narnian history. However, The Lion, the Witch and the Wardrobe remains the original publication starting point and the book that first presents the wardrobe portal to readers.