CS Lewis's 1950 tale of four children who enter the fantastical world of Narnia through a wardrobe beat contemporary favourites such as Harry Potter and The Gruffalo.
The top 50 children's books included much-loved classics such as the Wind in the Willows, Alice in Wonderland, the Secret Garden and the Railway Children.
But second place in the poll was taken by a picture book said to have sold a copy every minute since it was published in 1969, The Very Hungry Caterpillar by Eric Carle.
Third place was claimed by Enid Blyton's Famous Five Series, begun in 1942 and consisting of 21 books, but counting as one entry for the purposes of the poll, followed by A A Milne's Winnie the Pooh.
The best-loved author emerged as Roald Dahl, who boasts six books in the top 50. His most popular was The BFG, in fifth place.
The single JK Rowling title in the list, Harry Potter and the Half Blood Prince, was sixth.
The remainder of the top ten was The Faraway Tree by Enid Blyton; The Wind in the Willows by Kenneth Grahame; Alice in Wonderland by Lewis Carroll; and The Gruffalo by Julia Donaldson.
The poll of 4,000 respondents was conducted by the charity Booktrust, which runs the Governmentbacked Bookstart initiative giving free packs of books to children.
Viv Bird, director of Booktrust, said: "It's wonderful to see the enduring popularity of these books which are loved by generation after generation."
:: Top 50 Best Children's Books