Operation Blue Star was a military operation by the Indian Armed Forces conducted between 1 and 10 June 1984 to remove Jarnail Singh Bhindranwale and other Sikh militants from the Golden Temple (Harmandir Sahib), a holy site of Sikhism, and its adjacent buildings.

A long-standing movement advocating for greater political rights for the Sikh community had previously existed in the Indian state of Punjab, and in 1973, Sikh activists presented the Indian government with the Anandpur Sahib Resolution, a list of demands for greater autonomy for Punjab. The resolution was rejected by the Indian government. In July 1982, Harchand Singh Longowal, the president of the Sikh political party Shiromani Akali Dal, invited Bhindranwale, who was wanted by authorities, to take up residence in the Golden Temple to evade arrest. Bhindranwale had organized killer squads to eliminate supposed enemies of Sikhism. From the Harmandir Sahib complex, Bhindranwale orchestrated militants to kill hundreds of Hindus, and used terrorism to evoke fear among Hindus, hoping to incite their mass flight from Punjab. On 1 June 1984, after negotiations with the militants failed, Indian prime minister Indira Gandhi ordered the army to launch Operation Blue Star in haste, attacking the Golden Temple and scores of other Sikh temples and sites across Punjab which included killing civilians and devotees too.

The military underestimated the firepower possessed by the Sikh militants, whose armaments included Chinese-made rocket-propelled grenade launchers and ammunition with armour-piercing capabilities. Hoping to avoid damage to the holy site, Indian forces unsuccessfully assaulted the temple using light weaponry and quickly resorted to using heavy weapons, including tanks, helicopters and artillery to dislodge the well-fortified Sikh militants. Combat devolved into protracted urban warfare, with the Indian forces committing significant forces to slowly gain ground. Eventually, the Sikh militants ran out of most of their ammunition on 6 June, and by 10 June fighting had largely ceased, with the Indian forces in control of the complex. The Indian government attributed high civilian casualties to Sikh militants using pilgrims trapped inside the temple as human shields. However, Indian forces were aware that civilians were present inside, and the operation began on a Sikh religious day, the martyrdom day of Guru Arjan Dev, when many worshippers would be present. Many civilians were subject to extrajudicial killings by the military during the operation.
The Indian Army initially put the total number of casualties at 554 Sikh militants and civilians killed, and 83 killed (4 officers, 79 soldiers) and 236 wounded among government forces. Kuldip Nayar quotes Rajiv Gandhi, who allegedly admitted that nearly 700 soldiers were killed, a figure Gandhi reportedly revealed in September 1984, while addressing the National Students Union of India session in Nagpur. According to Ved Marwah, the army suffered 35% casualties.
According to a close associate of Bhindranwale, only 35 militants were killed and the rest left within the first few days of the operation. They left because of a devised plan in which they would launch a revolution against the state to form Khalistan so that the movement could live on. The belief of the militants was that it is better for some to live to fight another day. According to the associate, all those who left would die in the Punjab insurgency.

Five months after the operation, on 31 October 1984, Indira Gandhi was assassinated in retaliation by two Sikhs, Satwant Singh and Beant Singh.