Haridwar (/ˌhʌrɪˈdwɑːr/; Hindi: [ɦəɾɪd̪waːɾ] ^ⓘ; formerly Mayapuri) is a city and municipal corporation in the Haridwar district of Uttarakhand, India. With a population of 228,832 according to 2011 census, it is the second-largest city in the state and the largest in the district. Haridwar is located at the south western part of the state. By law, no meat, fish, & eggs are sold within the city. The reason for such prohibition is to maintain the religious purity and holiness of the pilgrimage city.

The city is situated on the right bank of the Ganges river, at the foothills of the Shivalik ranges. Haridwar lies in a doab region where people speak Khari Boli, which is a dialect of Hindi. The other districts of doab region lie in Western Uttar Pradesh. Haridwar is regarded as a holy place for Hindus, hosting important religious events and serving as a gateway to several prominent places of worship. The word 'Haridwar' means the gateway to the Lord Hari. The most significant of the events here is the Kumbha Mela, which is celebrated every 12 years in Haridwar. During the Haridwar Kumbh Mela, millions of Hindu pilgrims, devotees, and tourists congregate in Haridwar to perform ritualistic bathing on the banks of the Ganges to wash away their sins to attain moksha.

According to Puranic legend, Haridwar, along with Ujjain, Nashik, and Prayag, is one of four sites where drops of amrita, the elixir of immortality, accidentally spilled over from a kumbha (pitcher) while being carried by the celestial bird deity Garuda just after the Samudra Manthana, or the churning of the ocean of milk. Brahma Kund, the spot where the amrita fell, is believed to be located at Har ki Pauri (literally, "footsteps of the Lord") and is considered to be the most sacred ghat of Haridwar. It is also the primary centre of the Kanwar pilgrimage, in which millions of participants gather sacred water from the Ganges and carry it across hundreds of miles to dispense as offerings in Shiva shrines. It is additionally a passage for the Chota Char Dham (the four principal pilgrim destinations in Uttarakhand: Gangotri, Yamunotri, Kedarnath, and Badrinath). Today, the city is developing beyond its religious importance with the fast-developing industrial estate of the State Industrial Development Corporation of Uttarakhand (SIDCUL), and the close by township of Bharat Heavy Electricals Limited (BHEL), as well as its affiliated ancillaries.

The modern name of the town has two spellings: Haridwar and Hardwar. Each of these names has its own connotation.

In Sanskrit, the liturgical language of Hinduism, Hari means Vishnu, while dvāra means "gateway". So, Haridwar translates to "The Gateway to Vishnu". It earns this name because it is typically the place where pilgrims start their journey to visit a prominent temple of Vishnu: Badrinath Temple.

Similarly, Hara could also mean "Shiva". Hence, Hardwar could stand for "Gateway to Shiva". Hardwar is also a typical place for pilgrims to start their journey in order to reach Mount Kailash, Kedarnath, the northernmost Jyotirlinga and one of the sites of the smaller Char Dham pilgrimage circuit – all important places for worship for Hindus.

According to legend, it was in Haridwar that goddess Ganga descended when Shiva released the mighty river from the locks of his hair. The River Ganga, after flowing for 253 kilometres (157 mi) from its source at Gaumukh at the edge of the Gangotri Glacier, enters the Gangetic Plain for the first time at Haridwar, which gave the city its ancient name, Gangadwára.

In the annotations to her poetical illustration Hurdwar, a Place of Hindoo Pilgrimage, Letitia Elizabeth Landon provides information on this name derivation, and also the story of the supposed origin of the 'River Ganges'. The accompanying plate is engraved from a painting by Samuel Prout. In sacred writings, it has been differently specified as "Kapilasthan", "Gangadwar" and "Mayapuri".