Oliver Napoleon Hill was an American self-help author best known for his book Think and Grow Rich (1937), which is among the best-selling self-help books of all time. Hill's works emphasized that fervid expectations are essential to improving one's life. Most of his books promote principles to achieve "success."

Hill is a controversial figure, accused of fraud, with historians doubting many of his claims, such as meeting Andrew Carnegie and being an attorney. Despite this, his influence in the self-help genre remains significant.