Ronnie Bar-On was born in Tel Aviv in 1948. He completed his IDF service with the rank of Lieutenant-Colonel and served as Justice in the Military Court of Appeals in Judea, Samaria and Gaza. An attorney by profession, he holds a law degree from the Hebrew University of Jerusalem.

Bar-On has served, among others, as Chairman of the Council for the Organization of Sport-Gambling (1998-2001), member of the Central Committee of the Israel Bar (1995-2003) and the Jerusalem Regional Committee of the Israeli Bar, as well as a member of the Council for the Administrative Courts, the Advisory Commission to the Government Companies Authority, and the Public Defenders Commission. In addition, he served as Chairman of Administration of Beitar Yerushalayim and a member of the Administration of the Israel Football Association.

Elected to the 16th Knesset in 2003, he served as Chairman of the House Committee, and a member of the Constitution, Law and Justice and State Control Committees, as well as a substitute member of the Foreign Affairs and Defense Committee and a member of the Parliamentary Inquiry Committee on Violence in Sports and of the Environmental Lobby. He served as Minister of National Infrastructures and Minister of Science and Technology from January-May 2006.

In May 2006, reelected to the Knesset on the Kadima list, Ronnie Bar-On was appointed Minister of the Interior, serving until July 2007 when he was appointed Minister of Finance, a post he held until March 2009.

He is married and the father of three.