Catharine A. MacKinnon is the Elizabeth A. Long Professor of Law at Michigan Law and the long-term James Barr Ames Visiting Professor of Law at Harvard Law School. She specializes in sex equality issues under international and domestic (including comparative, criminal, and constitutional) law.

MacKinnon pioneered the legal claim for sexual harassment and, with Andrea Dworkin, created ordinances recognizing pornography as a civil rights violation and the Swedish model (Equality Model) for abolishing prostitution. The Supreme Court of Canada has largely accepted her approaches to equality, pornography, and hate speech, which have been influential internationally as well.

Representing Bosnian women survivors of Serbian genocidal sexual atrocities, MacKinnon, along with her co-counsel, won a damage award of $745 million in August 2000 in Kadic v. Karadzic under the Alien Tort Act, the first recognition of rape as an act of genocide.

Among the schools at which she has taught are Yale, Stanford, Chicago, Harvard, Osgoode Hall (Toronto), Basel (Switzerland), Hebrew University (Jerusalem), and Columbia. She was awarded residential fellowships at the Institute for Advanced Study, Stanford, the Wissenschaftskolleg zu Berlin, and the University of Cambridge.

MacKinnon's scholarly books include the casebook Sex Equality (2001/2007/2016), Are Women Human? (2006), Women's Lives, Men's Laws (2005), Only Words (1993), Toward a Feminist Theory of the State (1989), Feminism Unmodified (1987), and Sexual Harassment of Working Women (1979), as well as her most recent book, Butterfly Politics (2017 and 2018). She is widely published in journals, the popular press, and many languages.

MacKinnon practices and consults nationally and internationally, including with the UN, and works regularly with the Coalition Against Trafficking in Women and Equal Rights Amendment Coalition. Serving as the first special gender adviser to the prosecutor of the International Criminal Court (The Hague) from 2008 to 2012, she implemented her concept of "gender crime."

In 2014, she was awarded the Lifetime Achievement Award by the Association of American Law Schools Women's Division and was elected to the American Law Institute. In 2019, she was given the Woman of Vision Award from the National Organization for Women. MacKinnon is among the most widely cited legal scholars in the English language.