The Fourth Way is the book about a system of self-development as introduced by Greek-Armenian philosopher  G.I. Gurdjieff. It is a compilation of the lectures of  P. D. Ouspensky at London and New York City between the years 1921 through 1946, published posthumously. The term "The Fourth Way" has also come to be used as a general descriptive term for the body of ideas and teachings which Gurdjieff brought to the west from his study of eastern schools. Ouspensky was given the task of bringing these ideas to a wider audience in an unadulterated form by Gurdjieff. The Fourth Way  is considered to be the most comprehensive statement of Gurdjieff's ideas as taught by Ouspensky.

This book recounts P. D. Ouspensky's first meeting and subsequent association with George Gurdjieff. It is widely regarded as perhaps the most comprehensive account of Gurdjieff's system of thought available. Many followers regard it as a "fundamental textbook" of Gurdjieff's teachings and it is often used as a means of introducing new students to Gurdjieff's system of self-development.