The Harmandir Sahib (Punjabi: ਹਰਿਮੰਦਰ ਸਾਹਿਬ), also Darbar Sahib (Punjabi: ਦਰਬਾਰ ਸਾਹਿਬ, Punjabi pronunciation: [dəɾbɑɾ sɑhɪb] and informally referred to as the "Golden Temple", is the holiest Sikh gurdwara located in the city of Amritsar, Punjab, India. The city was founded in 1574 by the fourth Sikh guru, Guru Ram Das.The Harmandir Sahib was designed by the fifth guru, Guru Arjan, who had the cornerstone laid by the Muslim Sufi saint Sai Hazrat Mian Mir on 28 December 1588. Guru Arjan completed the Adi Granth, the holy scripture of Sikhism, in 1604 and installed it in the gurdwara.

There are four doors to get into the Harmandir Sahib, which symbolize the openness of the Sikhs towards all people and religions.The present-day gurdwara was rebuilt in 1764 by Jassa Singh Ahluwalia with the help of other Sikh Misls. In the early nineteenth century, Maharaja Ranjit Singh secured the Punjab region from outside attack and covered the upper floors of the gurdwara with gold, which gives it its distinctive appearance and its English name.

The Harmandir Sahib literally means the Temple of God. In 1578 CE Guru Ram Das excavated a tank, which subsequently became known as Amritsar (Pool of the Nectar of Immortality), giving its name to the city that grew around it. In due course, the Harmandir Sahib, was built in the middle of this tank and became the supreme centre of Sikhism. Its sanctum came to house the Adi Granth comprising compositions of Sikh Gurus and other saints considered to have Sikh values and philosophies, e.g., Baba Farid, and Kabir. The compilation of the Adi Granth was started by the fifth guru of Sikhism, Guru Arjan Dev Ji.

Guru Arjan Dev Ji conceived the idea of creating a central place of worship for the Sikhs and designed the architecture of Harmandir Sahib. Earlier the planning to excavate the holy tank (Amritsar or Amrit Sarovar ) was chalked out by Guru Amar Das, the Third Sikh Guru, but it was executed by Guru Ram Das under the supervision of Baba Budha. The land for the site was acquired by the earlier Guru Sahibs on payment or free of cost from the Zamindars (landlords) of native villages. The plan to establish a town settlement was also made and the construction work on the Sarovar (the tank) and the town started simultaneously in 1570. The work on both projects was completed in 1577. In December 1588, Guru Arjan initiated the construction of the gurdwara and the foundation stone was laid by Hazrat Mian Mir on 28 December 1588.The gurdwara was completed in 1604. Guru Arjan installed the Guru Granth Sahib in it and appointed Baba Buddha as the first Granthi (reader) of it on August 1604. In the mid-18th century it was attacked by the Afghans, by one of Ahmed Shah Abdali's generals, Jahan Khan, and had to be substantially rebuilt in the 1760s. However, in response a Sikh Army was sent to hunt down the Afghan force. The forces met five miles outside Amritsar and Jahan Khan's army was destroyed.

Blue Star was a military operation undertaken between 3 June and 6 June 1984. The Indian prime minister Indira Gandhi ordered the Indian Army to launch the operation. The army, led by General Kuldip Singh Brar, against his will, brought infantry, artillery and tanks into the Harmandir Sahib to put a stop to the Dharam Yudh Morcha led by Jarnail Singh Bhindranwale. During the Dharam Yudh Morcha thousands of Sikhs courted arrest. Fierce fighting ensued between Sikhs and the army, with heavy casualties on both sides. The Harmandir Sahib complex also suffered much damage during the attack, especially the holy Akal Takht. Within six months, on 31 October 1984, Indira Gandhi's Sikh bodyguards killed her for the sacrilege. This attack is regarded by Sikhs as a desecration of Sikhism's holiest shrine and discrimination against a minority in India. In 1986, the repairs performed on the Akal Takht Sahib after the attack, which the Rajiv Gandhi government had undertaken without consultation, were removed. A new Akal Takht Sahib was completed in 1999 by Kar Sevaks (volunteers)

Some of the architectural features of the Harmandir Sahib were intended to be symbolic of the Sikh world view.Instead of the normal custom of building a gurdwara on high land, it was built at a lower level than the surrounding land so that devotees would have to go down steps to enter it.In addition, instead of one entrance, Sri Harmandir Sahib has four entrances.

The gurdwara is surrounded by the Sarovar, a large lake or holy tank, which consists of Amrit ("holy water" or "immortal nectar") and is fed by the Ravi River. There are four entrances to the gurdwara, signifying the importance of acceptance and openness. There are three holy trees (bers), each signifying a historical event or Sikh saint. Inside the gurdwara there are many memorial plaques that commemorate past Sikh historical events, saints and martyrs, including commemorative inscriptions of all the Sikh soldiers who died fighting in World War I and World War II.

Much of the present decorative gilding and marblework dates from the early 19th century. All the gold and exquisite marble work were conducted under the patronage of Hukam Singh Chimni and Emperor Ranjit Singh, Maharaja of the Sikh Empire of the Punjab. The Darshani Deorhi Arch stands at the beginning of the causeway to the Harmandir Sahib; it is 62 metres (203 ft) high and 6 metres (20 ft) in width. The gold plating on the Harmandir Sahib was begun by Ranjit Singh and was finished in 1830. Maharaja Ranjit Singh was a major donor of wealth and materials for the shrine.