Tzachi was born in Jerusalem, in 1957.
He is the son of Emmanuel Hanegbi and Geula Cohen, who fought against the British rule over Palestine as members of the Hebrew underground group "Lehi", until the establishment of the State of Israel in 1948.
Tzachi Hanegbi grew up and finished high-school in Tel-Aviv. In October 1974 he joined the IDF and was assigned to be a military journalist in the army newspaper "BaMahane". After a determined struggle to raise his medical profile, Tzachi volunteered to join the Paratroopers' 35th Division, where he served as a combat soldier in Battalion 202 from August 1975 until completing his mandatory service in October 1977. As a reservist he served as a combat soldier in the Paratroopers' Reserve Division, and fought among its ranks in the first Lebanon War (1982).
In 1977 Tzachi began his academic studies in the Hebrew University in Jerusalem. In 1982 he successfully completed his BA in International Relations, and in 1994 received his LLB of the Law school of the Hebrew University in Jerusalem. Tzachi completed his internship at the Bar-On law office in Jerusalem, and was accepted to the Israel Bar Association in November 1994.
In 1979 Tzachi was elected as the head of the Jerusalem students' union, and in 1980 he was elected as head of the National Student Union of Israel. In these capacities Tzachi fought successfully to raise students' salaries, to lower university tuition and to improve the conditions in students' dorms. At the same time, Tzachi led the protests against anti-Israeli activities organized by radical Arab student cells.
In 1982 Tzachi led a group of 17 students to the top of a monument in the Sinai town of Yamit to protest the eminent uprooting of the Jewish settlements in the Sinai Peninsula as part of the peace agreement with Egypt. The group remained atop the monument for 23 days. They came down peacefully on the last day of the Israeli presence in the region, in order to avoid direct conflict with IDF soldiers.
In 1984 Tzachi was appointed as an adviser to Foreign Minister Yitzhak Shamir, and in 1986 he was made Head of Prime Minister Shamir's Bureau.
In November 1988 Tzachi was elected for the first time as a Member of the Knesset for the Likud Party. He served in the Israeli parliament for 22 consecutive years, until December 2010. During the 13th Knesset (1992-1996) Tzachi chaired the Economy Committee. In this capacity he initiated (together with MK Avraham Burg) the establishment of the Road Safety Authority, and promoted the reform in the gasoline market, and the building of Israel's cross-country Road number 6.
In 1996 Tzachi was appointed Minister of Health in Binyamin Netanyahu's government. At the end of that year he was appointed Minister of Justice. As Minister of Justice Tzachi presented to the Knesset legislation intended to enhance courts' powers in combating domestic violence, to make citizens dealings with the state more efficient, to help police battle organized crime and money laundering, and more.
In 2001 Tzachi was appointed Minister of the Environment in Ariel Sharon's government. He promoted the "recycling revolution", forced the public transportation cooperatives to diminish pollution, and led the government's efforts towards the recovery of the Yarkon and Kishon rivers. For a few months, leading to the elections for the 16th Knesset, Tzachi also held the position of Minister of Transportation.
In February 2003 Tzachi was appointed Minister of Public Security in Ariel Sharon's second government. In this capacity, he initiated the following decisions, among others:
- February 2003 – the decision to allow Jews and tourists to visit the Temple Mount after Arafat closed the site to non-Arabs in September 2000. Since then the routine of visits has continued undisturbed.
- March 2004 – the decision to establish within the police a national unit dedicated to fight financial crimes.
- May 2004 – the decision to appoint Moshe Karadi as Inspector General – the head of the police. This decision surprised many who expected that one of the more senior candidates will be chosen. Hanegbi explained that the appointment was a means to reinvigorate the senior ranks of the police, and his recommendation was unanimously approved by the government.
In September 2004, following the Attorney General's decision to order an investigation of political appointments made within the Ministry of the Environment, Tzachi Hanegbi resigned from his role as the Minister in charge of the police. He was then appointed by Prime Minister Sharon as a Minister in the Prime Minister's Office in charge of the Secret Services and the strategic dialogue between Israel and the United States. In this capacity Hanegbi was in charge of responding on behalf of the Prime Minister's Office to reports of the State Comptroller regarding the Institute for Intelligence and Special Operations (Mossad), the Israel Security Agency (Shabak), and the Atomic Energy Commission. In November 2005 Hanegbi led Israel's delegation to Washington for the strategic discussions with US administration, which dealt with the region's sensitive political and security issues.
In December 2005 Tzachi Hanegbi accepted Ariel Sharon's call to join the new political movement he had established – "Kadima". Tzachi insisted that he must resign from the Knesset, as his public mandate belonged to the Likud.
In preparation for the 17th Knesset, which took place in March 2006, Tzachi was asked by the Prime Minister, Ehud Olmert, to head Kadima's election headquarters. Kadima won the elections by a wide margin, and on May 2006 Tzachi Hanegbi was appointed as Chairman of the Foreign Affairs and Security Committee, a role he filled until December 2010.
After the Second Lebanon War (2006) Tzachi led the committee in writing an extensive report about the war, which was published in December 2007. The report's conclusions included harsh criticism of the political and military echelons, as well as many concrete recommendations, some of which are still classified.
During 2008 the Foreign Affairs and Security Committee had passed two significant laws: The Reserve Service Act, which solidifies the rights and benefits of reserve soldiers; and the National Security Council Act, which formalizes, in the spirit of the Winograd Report, the NSCs responsibility to coordinate the government's decision-making process on national security issues.
When the Likud regained the government in 2009, Prime Minister Netanyahu and Defense Minister Barak decided to keep the position of the Chairman of the Foreign Affairs and Security Committee in Tzachi Hanegbi's hands. It was the first time in the Knesset's history that the prestigious position was held by a member of the opposition.
In July 2010, after six years of investigation and trial, the Jerusalem Magistrate court had decided, by majority vote, to acquit Tzachi from all the charges pertaining to political appointments. However, in a secondary case two out of three judges had decided to convict him of perjury before the election committee in the year 2002. Following the court's decision, Tzachi announced his resignation from the Knesset in December 2010.
In July 2012, Hanegbi resigned from the "Kadima" movement, following the dissolution of the unity government, and returned to the "Likud" party. In January 2012 Hanegbi was elected a Member of the 19th Knesset.
Tzachi occasionally writes articles on contemporary issues for the "Jerusalem Post" and accepts offers by the Israeli and international media to express his opinion on various issues relating to national security, foreign policy, social issues and the economy, based on his 30 years of experience in the public service, for the benefit of the State of Israel.
Tzachi lives in Mevasseret Zion, and is married since 1983 to Randi, who had made aliyah from the United States in 1980. They have four sons (Edan, 24, had recently completed his army service as an officer; Stav and Matan, both 19, are now serving in combat units; and Liav, 8).