The Tokyo subway sarin attack 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 during rush hour, killing 13 people, severely injuring 50, and causing temporary vision problems for nearly 1,000 others. The attack was directed against trains passing through Kasumigaseki and Nagatachō, where the National Diet is headquartered in Tokyo.

Aleph , better known by their former name Aum Shinrikyo , is a Japanese new religious movement and 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.