Ringerike is a Norwegian municipality located in the former Buskerud county in Viken county. Its administration center is Hønefoss. The municipality borders in the north to Sør-Aurdal and Søndre Land, in the east to Gran, Jevnaker, Lunner and Oslo, in the south to Bærum and Hole, and in the west to Modum, Krødsherad and Flå. Ringerike thus has eleven neighboring municipalities. The municipality had 30,442 inhabitants as of 1 January 2019.

Ringerike municipality arose on 1 January 1964, after a municipal merger between the municipalities of Hole, Tyristrand, Hønefoss, Norderhov and Ådal. A smaller part of Flå municipality was also added to the new large municipality. Hole withdrew from the large municipality from 1 January 1977 and became an independent municipality again. Ringerike is one of the medium-sized urban municipalities in Norway and it is the largest forest industry municipality, where the business community is largely based on timber. However, significant agriculture is also practiced there. Industrial, trade and service activities are also growing.

The name Ringerike is composed of the two words hringr (ring) and riki (kingdom or landscape), and was originally used for a much larger geographical area than that covered by the modern municipality, namely the landscape area called Ringerike. The origins date back to the first named kings who lived in Ringerike and as far back as Norwegian history is written. It is believed that the first "ring kings" settled (in a ring) around the Tyrifjord, and that this may have something to do with the name.