Nikkō (日光市, Nikkō-shi, IPA: [ɲikkoꜜːɕi]) is a city in Tochigi Prefecture, Japan.

The shrine of Nikkō Tōshō-gū was completed in 1617 and became a major draw of visitors to the area during the Edo period.

A number of new roads were built during this time to provide easier access to Nikkō from surrounding regions.

During the Meiji period, Nikkō developed as a mountain resort, and became particularly popular among foreign visitors to Japan.

Nikkō was incorporated as a town in 1889, part of Kamitsuga District, with the establishment of the modern municipalities system.

In March 2006, Nikkō absorbed the neighboring city of Imaichi, the town of Ashio from Kamitsuga District, the town of Fujihara, and the village of Kuriyama, both from Shioya District, to create what is officially the new and expanded city of Nikkō.

Nikkō has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 24 members.

In terms of national politics, the town is part of Tochigi 2nd district of the lower house of the Diet of Japan.

Nikkō is heavily dependent on tourism to its historical and scenic sites and hot spring resorts.

Hydroelectric power production, food processing, and the non-ferrous metals industry are also important components of the economy.

The city has three public high schools operated by the Tochigi Prefectural Board of Education.