Barzilai was born on 11 January 1958 in Tel Aviv to parents who had survived the Holocaust.

Barzilai served as a professor at Tel Aviv University in the political science department and the law school.

In 2004, he moved to the University of Washington where he had been a professor in the Law, Societies, and Justice Program,[3] Comparative Law and Society Studies Center,[4] and in the Jackson School of International Studies.

He was active in international, Israeli and Israeli-Palestinian human rights organizations and has advised senior politicians and NGOs on issues of law and politics.

[6] Gad Barzilai is best known for his critical analysis of law as a dimension in political power, which should be understood through using combined methodologies of socio-political-legal studies.