In 1979 she published Women in Western Political Thought, in which she details the history of the perceptions of women in western political philosophy.

Her 1989 book Justice, Gender, and the Family is a critique of modern theories of justice ranging from the liberalism of John Rawls and Robert Nozick to the communitarianism of Alasdair MacIntyre and Michael Walzer. According to Okin, these theorists write from a male perspective that wrongly assumes that the institution of the family is just. She believes that the family perpetuates gender inequalities throughout all of society, particularly because children acquire their values and ideas in the family's sexist setting, then grow up to enact these ideas as adults. If a theory of justice is to be complete, Okin asserts that it must include women and it must address the gender inequalities she believes are prevalent in modern-day families.

Okin was born in 1946 in Auckland, New Zealand. She earned a bachelor's degree from the University of Auckland in 1967, a master of philosophy degree from Oxford in 1970 and a doctorate from Harvard in 1975. She taught at the University of Auckland, Vassar, Brandeis and Harvard before joining Stanford's faculty.

Okin became the Marta Sutton Weeks Professor of Ethics in Society at Stanford University in 1990.

She died at her home in Lincoln, Massachusetts on March 3rd 2004.