In March 1981, he was suspended for a year for his participation in a protest against Arab violence on campus that included locking the rector, Raphael Mechoulam, in his room.

[11] Katz along with Benjamin Netanyahu, Silvan Shalom and Limor Livnat announced that they would resign from the government within two weeks if Sharon did not agree to hold a national referendum on the pull out plan.

[13] In March 2007, the Israel Police recommended indicting Katz on charges of fraud and breach of trust linked to political appointments at the Ministry of Agriculture during his tenure as minister.

[19][20] In February 2010, Katz was ordered by the High Court of Justice to issue instructions based on a committee's findings that gender segregation in public buses was illegal and that separate seating could not be coerced, as Haredis were doing.

According to Katz, the move was intended to incentivize settlers to use armor-protected public transportation within the West Bank, which would ostensibly reduce state spending on stationing military and security escorts for non-armored, private vehicles.

[29][30] On 1 January 2024, Katz assumed the role of the Minister of Foreign Affairs for the second time, following the Knesset's approval of a power-sharing agreement that led to the replacement of Eli Cohen.

[31] In July 2024, he attended the 2024 NATO Summit in Washington, D.C.[32] Katz warned of the Iran-Russia alliance and the dangers posed by Iran and China, and also met with the foreign ministers of Denmark, the Netherlands, the Czech Republic, the United States, Germany, South Korea and Canada.

[43] He opposes any territorial retreat from the Golan Heights, captured from Syria during the Six-Day War, deeming it "an integral part of Israel and vital for its security and protection.

[46] In the aftermath of the 2016 Brussels bombings, Katz caused some controversy when he made "harsh"[47] comments on Israel Radio about the inability of Belgium and the Western world to fight Islamic terrorism effectively.

"[47][48] The "chocolate-eating Belgians" remark was widely quoted in the Western media and ridiculed on Twitter,[49] and Katz was accused by Israeli pundits of giving Israel a bad image abroad as a result.

[50] In March 2016, Katz introduced a bill to the Knesset to enable the Israeli government to deport the families of terrorists, if they are found to have been aware of, to have encouraged, or to have aided the act.

[52] During an interview on Israeli TV, Katz quoted Yitzhak Shamir by saying that Poles "suckled anti-Semitism from their mothers' breasts," allegedly causing Polish Prime Minister Mateusz Morawiecki to cancel his visit to Israel in February 2019.

[55] In 2024, Ömer Çelik, the former Turkish Minister of European Union Affairs and spokesperson of the Justice and Development Party, likened Katz to Nazi leader Adolf Hitler's top diplomat Joachim von Ribbentrop due to his radical and provocative remarks during the Invasion of the Gaza Strip.