Nikk? (?亙?撣?Nikk?-shi, literally 'sunlight') is a city in the mountains of Tochigi Prefecture, Japan. Approximately 140 km north of Tokyo and 35 km west of Utsunomiya, the capital of Tochigi Prefecture, it is a popular destination for Japanese and international tourists.

Attractions include the mausoleum of shogun Tokugawa Ieyasu (Nikk? T?sh?-g贖) and that of his grandson Iemitsu (Iemitsu-by? Taiy贖-in), and the Futarasan Shrine, which dates to the year 767. There are also many famous hot springs (onsen) in the area.

Elevations range from 200 to 2,000 m. The mountains west of the main city are part of Nikk? National Park and contain some of the country's most spectacular waterfalls and scenic trails.