Frederick Warne & Co. is a British publisher founded in 1865. It is known for children's books, particularly those of Beatrix Potter, and for its Observer's Books.

Frederick Warne & Co. was founded in Covent Garden in July 1865 by London bookseller and publisher, Frederick Warne. The business was one successor to Routledge, Warne, Routledge (thus from 1858), the publishing partnership of Warne with his brother-in-law George Routledge and the eldest of Routledge's sons. The other successor was George Routledge & Sons.

During the second half of the nineteenth century, the company built a reputation for publishing children's books, publishing illustrated books by well-known authors and artists as Edward Lear, Kate Greenaway and Walter Crane. The company also published a 'Pictorial' series of books of collections of short essays and illustrations on many non-fiction topics.