O'Connor earned her B.A., J.D., and Ph. D. degrees from SUNY-Buffalo. She taught at Emory University from 1977 until moving to American University in 1995.
O'Connor has written, co-authored, or edited several books, including American Government: Continuity and Change, 10th ed. (2009) and Women, Politics and American Society, 4th ed. (2004), Women in Congress: Running, Winning and Ruling (2002), and No Neutral Ground: Abortion Politics in an Age of Absolutes (1996). She has published numerous monographs, book chapters, and articles in the leading social science and political science journals and law reviews. She is also an active member of the American Political Science Association, the past chair of the Law and Courts section of the APSA, the past president of the Women's Caucus for Political Science, Southern Political Science Association and the National Capital Area Political Science Association. She is also a member of various editorial boards, including Law & Policy.