The Description of a New World, Called The Blazing-World, better known as The Blazing World, is a 1666 work of prose fiction by English writer Margaret Cavendish, the Duchess of Newcastle. It has been described as an early forerunner of science fiction.

Margaret Cavendish was born Margaret Lucas in 1623 to an aristocratic, royalist family in Colchester, Essex. She was privately, albeit relatively basically, educated in childhood, but appears to have read widely on a range of topics more usually reserved for male scholars. She became a remarkably prolific writer in a variety of genres, and was unusual for publishing under her own name when most women authors only wrote anonymously.As a young woman Cavendish travelled with Charles Is wife, Henrietta Maria, into exile in France. In 1645 she married William Cavendish, Marquess of Newcastle-upon-Tyne, who was more than 30 years her senior. Although denying he had secretly authored her works, as some detractors insisted, Cavendish openly acknowledged her husband as an important influence on her work.