Joan Greco was born in the Bronx, New York to mail handler Ralph Greco and homemaker Iris Greco.  After attending Catholic elementary schools, she went on to the Bronx High School of Science, the University of Pennsylvania (B.A. Psychology), and Harvard Law School (J.D. magna cum laude).

At Harvard, Greco met Fred W. Friendly, who, with Harvard Law professors Arthur R. Miller, Charles Ogletree, and Charles Nesson was creating a series of programs for PBS called The Constitution: That Delicate Balance.   The programs used a format, developed by Friendly and the professors, in which panelists were placed in hypothetical scenarios that put their values to the test.  Greco started assisting the group with research and the development of scenarios.  The first program in which Greco developed the hypothetical scenarios,  The Sovereign Self: Right to Live, Right to Die, won an Emmy award.

Greco became an editor of the Harvard Law Review, and graduated HLS magna cum laude.  She went on to clerk for Ruth Bader Ginsburg while she was at the U.S. Court of Appeals for the District of Columbia Circuit, and then to clerk for Sandra Day O’Connor at the United States Supreme Court.

Following the clerkships, Greco spent a brief period at the New York law firm of Davis, Polk and Wardwell.  But she preferred work as an independent consultant.  In 1990 she left the firm and has been self-employed since.

Primarily in association with the Fred Friendly Seminars (and its predecessor, Media and Society Seminars), Greco has written the hypothetical scenarios for, or has written and produced, programs on a huge variety of subjects, including, for example,  personal ethics, affirmative action, bioterrorism, child welfare systems, pandemic flu, nanotechnology, energy policy, genetics, end-of-life decisions, judicial elections, severe mental illness, journalism in wartime, and the future of symphony orchestras.

In addition to the Fred Friendly Seminars, Greco has also worked with institutions such as the Washington National Cathedral, the U.S. Comedy Festival, Harvard University, NYUWagner Research Center for Leadership in Action, and the information retrieval company H5.

Greco lives in New York City with her two fantastic children.