"Rand's writing (both fiction and non-fiction) emphasizes the philosophic concepts of objective reality in metaphysics, reason in epistemology, and rational egoism in ethics. In politics she was a proponent of laissez-faire capitalism and a staunch defender of individual rights, believing that the sole function of a proper government is protection of individual rights (including property rights)."

 She was profoundly moved by the city's skyline, later describing it in one of her novels, The Fountainhead: "I would give the greatest sunset in the world for one sight of New York's skyline, the sky over New York and the will of man made visible. What other religion do we need? I feel that if a war came to threaten this, I would throw myself into space, over the city, and protect these buildings with my body."

Rand's Objectivist philosophy encompasses positions on metaphysics, epistemology, ethics, politics and aesthetics. While there have been "objectivist" theories in the past, Rand's Objectivism reflects a specific world view and should be distinguished from other theories such as Plato's metaphysical realism. Along with Nathaniel Branden, his wife Barbara, and others including Alan Greenspan and Leonard Peikoff (jokingly designated "The Collective"), Rand launched the Objectivist movement to promote her philosophy.

Rand held that the only moral social system is laissez-faire capitalism. Her political views were strongly individualist and hence anti-statist and anti-Communist. She exalted what she saw as the heroic American values of rational egoism and individualism. As a champion of rationality, Rand also had a strong opposition to mysticism and religion, which she believed helped foster a crippling culture acting against individual human happiness and success. Rand detested many prominent liberal and conservative politicians of her time, including prominent anti-Communists, such as Harry S. Truman, Ronald Reagan, Hubert Humphrey, and Joseph McCarthy.

Rand's theory of sex is implied by her broader ethical and psychological theories. Far from being a debasing animal instinct, she believed that sex is the highest celebration of our greatest values. Sex is a physical response to intellectual and spiritual values – a mechanism for giving concrete expression to values that could otherwise only be experienced in the abstract. In Atlas Shrugged, she writes "Tell me what a man finds sexually attractive and I will tell you his entire philosophy of life. Show me the woman he sleeps with and I will tell you his valuation of himself."

Rand's novels continue to be widely sold and read, with more than 22 million books sold (as of 2005), and 500,000 more being sold each year.[63] Following her death, continued conflict within the Objectivist movement led to establishment of independent organizations claiming to be her intellectual heirs. Rand and Objectivism are less well known outside North America, although there are pockets of interest in Europe, Australia, and New Zealand. Her novels are reported to be popular in India[64] and to be gaining an increasingly wider audience in Africa. She also enjoyed some popularity in Israel, through the early work of Moshe Kroy. Generally, her work has had little effect on academic philosophy; her followers have been largely drawn from the non-academic world. However, in recent years there has been notable interest in Ayn Rand's philosophy in academic philosophy.