Napoleon Hill was an American self-help author and motivational speaker, best known for his landmark book Think and Grow Rich. Considered one of the earliest pioneers of the personal development movement, Hill studied the lives of highly successful people such as Andrew Carnegie, Thomas Edison, and Henry Ford to identify universal principles of achievement. His teachings emphasize the power of desire, belief, persistence, and organized planning, forming a timeless framework for success that continues to influence leaders, entrepreneurs, and individuals worldwide.