Born in the Baka neighbourhood of Jerusalem, during his IDF national service he was in the Intelligence Corps. After leaving the army he began studying for a BA in economics, later gaining an MBA from the Hebrew University of Jerusalem.
He worked for four and half years in the Ministry of Finance, before joining Bezeq, initially as an assistant to CEO Ami Erel, later becoming VP of Human Resources. In 2003 he became CEO of Bezeq International, and went onto become CEO of Bezeq in 2006, a position he held until leaving the company in 2013.
Prior to the 2015 Knesset elections he was amongst the founders of the new Kulanu party. Despite not being elected to the Knesset, he was appointed Minister of Environmental Protection. In order to expand his majority in the Knesset, Prime Minister Netanyahu signed a coalition agreement with the Yisrael Beiteinu party on May 24, 2015, appointing their leader Avigdor Lieberman to replace Moshe Ya'alon as Defense Minister. Later that week Gabai resigned in protest of Lieberman's inclusion.
Gabai lives in Tel Aviv, and is married with three children.
Sources: Teig, Amir. “Suddenly, Bezeq CEO stepping down,” Haaretz (January 21, 2013)
Hoffman, Gil. “Kahlon officialy registers new Kulanu party,” Jerusalem Post (December 11, 2014)
Sharon, Itamar. “Who's who in Netanyahu's 2015 government,” Times of Israel (May 15, 2015)