The Haanel family was of Swedish extraction, but had lived in Silesia, Prussia, before emigrating to Canada and thence to the United States.
In St. Louis: History of the Fourth City, the author Walter B. Stevens wrote that "Charles F. Haanel was born in Ann Arbor, Michigan, the son of Hugo and Emeline (Fox) Haanel." He was the fourth of six children. According to Stevens, "The family moved to St. Louis, Missouri when Charles was a child. His first job was as an office boy for the National Enameling & Stamping Company in St. Louis, and he worked for this firm in varying capacities for fifteen years before striking out on his own as a writer and businessman."
In 1885 he married Esther M. Smith. They had one son and two daughters. In 1891 his wife died. In 1908 he married for the second time, to Margaret Nicholson of St. Louis, whose father was W. A. Nicholson.
He was a member of the Republican Party, a Freemason and Shriner affiliated with St. Louis Keystone Lodge No.243, (A.F. & A.M.) and a supporter of the Missouri Athletic Club. He was a member of Pi Gamma Mu Fraternity, a Fellow of the London College of Psychotherapy, a member of the Authors League of America; a member of the American Society of Psychical Research; a member of the Society of Rosicrucians; a member of the American Suggestive Therapeutical Association; and a member of the Science League of America. During his life, Haanel earned and received several honorary academic degrees, including hon. Ph.D., College National Electronic Institute; Metaphysics, Psy. D., College of Divine Metaphysics; and M.D., Universal College of Dupleix, India.
When Haanel died on November 27, 1949; he was 83 years old. His ashes were buried in Bellefontaine Cemetery, St. Louis.
Haanel's book The Master Key System was published in 1912, when he was 46 years old. It is written in the form of a course in New Thought, mental development, financial success, and personal health. The book was heavily promoted in the pages of Elizabeth Towne's New Thought magazine The Nautilus. By 1933 it had allegedly sold over 200,000 copies worldwide. Haanel practiced the financial principles he preached, and was a self made success who owned several major companies. According to Stevens, writing in 1909, "He was president of the Continental Commercial Company, president of the Sacramento Valley Improvement Company, and president of the Mexico Gold & Silver Mining Company."
The original Master Key System contained 24 parts or modules of study. The allegedly "lost" chapters of the Master Key System, chapters 25-28, which are found in some editions, are not original, but have been copied from the chapters 11-14 of A book about You. Among the key points of Haanel's system are what he refers to as the laws of concentration, attraction, and harmonious thinking and action. Unique to the Master Key System is a set of exercises that accompany each chapter, and which are systematically building upon each other — they are what makes the Master Key System a system. Another important aspect of the Master Key System is the element of "Truth". The understanding of "Truth" is derived from the understanding that Spirit is all there is, and that it cannot be other than perfect. Truth provides readers/students with certainty, courage and determination to change their life for the better.
In addition to the Master Key System, Haanel wrote several other books including Mental Chemistry, published in 1922, The New Psychology, published in 1924, A Book about You, published in 1927, and The Amazing Secrets of the Yogi, co-authored with Victor Simon Perera and published in 1937.
In 1919, Napoleon Hill wrote Haanel a letter thanking him for The Master Key System. In the letter Hill stated, "My present success and the success which has followed my work as President of the Napoleon Hill Institute is due largely to the principles laid down in The Master-Key System."
Haanel was quoted in the best-selling self-help book The Secret by Rhonda Byrne, published in 2007.