John Bordley Rawls (/rɔːlz/; February 21, 1921 – November 24, 2002) was an American moral and political Philosopher in the liberal tradition. He held the James Bryant Conant University Professorship at Harvard University and the Fulbright Fellowship at the University of Oxford. Rawls received both the Schock Prize for Logic and Philosophy and the National Humanities Medal in 1999, the latter presented by President Bill Clinton, in recognition of how Rawls's work "helped a whole generation of learned Americans revive their faith in democracy itself."

Rawls attended the Calvert School in Baltimore for six years, before transferring to the Kent School, an Episcopalian preparatory school in Connecticut. Upon graduation in 1939, Rawls attended Princeton University where he graduated summa cum laude and was accepted into The Ivy Club and the American Whig-Cliosophic Society. During his last two years at Princeton, he "became deeply concerned with theology and its doctrines." He considered attending a seminary to study for the Episcopal priesthood and wrote an "intensely religious senior thesis (BI)." At Princeton, Rawls was influenced by Norman Malcolm, Wittgenstein's student.

He completed his Bachelor of Arts degree in 1943, and enlisted in the Army in February of that year.

In early 1946, Rawls returned to Princeton to pursue a doctorate in moral philosophy.

He married Margaret Fox, a Brown University graduate, in 1949.

After earning his PhD from Princeton in 1950, Rawls taught there until 1952 when he received a Fulbright Fellowship to Oxford University (Christ Church), where he was influenced by the liberal political theorist and Historian Isaiah Berlin and the legal theorist H. L. A. Hart. After returning to the United States he served first as an assistant and then associate professor at Cornell University. In 1962 he became a full professor of philosophy at Cornell, and soon achieved a tenured position at MIT. That same year he moved to Harvard University, where he taught for almost forty years and where he trained some of the leading contemporary figures in moral and political philosophy, including Thomas Nagel, Allan Gibbard, Onora O'Neill, Adrian Piper, Elizabeth S. Anderson, Christine Korsgaard, Susan Neiman, Claudia Card, Thomas Pogge, T.M. Scanlon, Barbara Herman, Joshua Cohen, Thomas E. Hill, Jr., Gurcharan Das, Andreas Teuber, Samuel Freeman and Paul Weithman.

Rawls's A Theory of Justice (1971) includes a thought experiment he called the "original position". The intuition motivating its employment is this: the enterprise of political philosophy will be greatly benefited by a specification of the correct standpoint a person should take in his or her thinking about justice. When we think about what it would mean for a just state of affairs to obtain between persons, we eliminate certain features (such as hair or eye color, height, race, etc.) and fixate upon others. Rawls's original position is meant to encode all of our intuitions about which features are relevant, and which irrelevant, for the purposes of deliberating well about justice.

In his 1990 introduction to the field, Will Kymlicka wrote that "it is generally accepted that the recent rebirth of normative political philosophy began with the publication of John Rawls's A Theory of Justice in 1971." Rawls has often been described as the most important political Philosopher of the 20th century. He has the unusual distinction among contemporary political Philosophers of being frequently cited by the courts of law in the United States and Canada and referred to by practising politicians in the United States and the United Kingdom.

In Political Liberalism (1993), Rawls turned towards the question of political legitimacy in the context of intractable philosophical, religious, and moral disagreement amongst citizens regarding the human good. Such disagreement, he insisted, was reasonable – the result of the free exercise of human rationality under the conditions of open enquiry and free conscience that the liberal state is designed to safeguard. The question of legitimacy in the face of reasonable disagreement was urgent for Rawls because his own justification of Justice as Fairness relied upon a Kantian conception of the human good that can be reasonably rejected. If the political conception offered in A Theory of Justice can only be shown to be good by invoking a controversial conception of human flourishing, it is unclear how a liberal state ordered according to it could possibly be legitimate.

In 1995 he suffered the first of several strokes, severely impeding his ability to continue to work. He was nevertheless able to complete a book titled The Law of Peoples, the most complete statement of his views on international justice, and shortly before his death in November 2002 published Justice As Fairness: A Restatement, a response to criticisms of A Theory of Justice.

Rawls died on 24 November 2002 and is buried at the Mount Auburn Cemetery in Massachusetts.

John Rawls is also the subject of A Theory of Justice: The Musical!, an award-nominated musical billed as an 'all-singing, all-dancing romp through 2,500 years of political philosophy'. The musical premiered at Oxford in 2013 and was revived for the Edinburgh Fringe Festival.