The Japanese cult Aum Shinrikyo carries out a sarin gas attack on the Tokyo subway, killing 12 and wounding over 1,300 people.

The Tokyo subway sarin attack (, Chikatetsu Sarin Jiken, "Subway Sarin Incident") was an act of domestic terrorism perpetrated on 20 March 1995, in Tokyo, Japan, by members of the cult movement Aum Shinrikyo. In five coordinated attacks, the perpetrators released sarin on three lines of the Tokyo Metro (then Teito Rapid Transit Authority) during rush hour, killing 14 people, severely injuring 50 (some of whom later died), and causing temporary vision problems for nearly 1,000 others. The attack was directed against trains passing through Kasumigaseki and Nagatach, where the Diet (Japanese parliament) is headquartered in Tokyo.The group, led by Shoko Asahara, had already carried out several assassinations and terrorist attacks using sarin, including the Matsumoto sarin attack nine months earlier. They had also produced several other nerve agents, including VX, and attempted to produce botulinum toxin and had perpetrated several failed acts of bioterrorism. Asahara had been made aware of a police raid scheduled for March 22 and had planned the Tokyo subway attack in order to hinder police investigations into the cult and perhaps spark the apocalypse they believed in. The leader also wanted to start a Third World War.

In the raid following the attack, police arrested many senior members of the cult. Police activity continued throughout the summer, and over 200 members were arrested, including Asahara. Thirteen of the senior Aum management, including Asahara himself, were sentenced to death and later executed; many others were given prison sentences up to life. The attack remains the deadliest terrorist incident in Japan as defined by modern standards.

Aleph (Japanese: アレフ, Hepburn: Arefu), formerly Aum Shinrikyo (オウム真理教, Oumu Shinrikyō, literally 'Supreme Truth'), is a Japanese doomsday cult founded by Shoko Asahara in 1987. It carried out the deadly Tokyo subway sarin attack in 1995 and was found to have been responsible for the Matsumoto sarin attack the previous year.

The group says that those who carried out attacks did so secretly, without being known to other executives and ordinary believers. Asahara insisted on his innocence in a radio broadcast relayed from Russia and directed toward Japan.On 6 July 2018, after exhausting all appeals, Asahara and six followers were executed as a punishment for the 1995 attacks and other crimes, and the remaining six on death row were executed on 26 July. At 12:10 am, on New Year's Day 2019, at least nine people were injured (one seriously) when a car was deliberately driven into crowds celebrating the new year on Takeshita Street in Tokyo. Local police reported the arrest of Kazuhiro Kusakabe, the suspected driver, who allegedly admitted to intentionally ramming his vehicle into crowds to protest his opposition to the death penalty, specifically in retaliation for the execution of the aforementioned Aum cult members.

Aum Shinrikyo, which split into Aleph and Hikari no Wa in 2007, had already been formally designated a terrorist organization by several countries, including Russia, Canada, Kazakhstan, the United States, as well as the European Union.The Public Security Intelligence Agency considered Aleph and Hikari no Wa to be branches of a "dangerous religion" and it announced in January 2015 that they would remain under surveillance for three more years. The Tokyo District Court canceled the extension to surveillance of Hikari no Wa in 2017 following legal challenges from the group, but continued to keep Aleph under watch. The government appealed the cancellation, and in February 2019, the Tokyo High Court overturned the lower court's decision, reinstating the surveillance, citing no major changes between Aum Shinrikyo and Hikari no Wa.