Objectivism: The Philosophy of Ayn Rand is a 1991 book by the philosopher Leonard Peikoff, in which the author discusses the ideas of his mentor, Ayn Rand. Peikoff describes it as "the first comprehensive statement" of Rand's philosophy, Objectivism. The book is based on a series of lecture courses that Peikoff first gave in 1976 and that Rand publicly endorsed. Peikoff states that only Rand was qualified to write the definitive statement of her philosophic system, and that the book should be seen as an interpretation "by her best student and chosen heir." The book is volume six of the "Ayn Rand Library" series edited by Peikoff.

Objectivism is a philosophical system named and developed by Russian-American writer and philosopher Ayn Rand. She described it as "the concept of man as a heroic being, with his own happiness as the moral purpose of his life, with productive achievement as his noblest activity, and reason as his only absolute".