Jevnaker is a municipality in Viken county, Norway. The administrative centre of the municipality is the village of Jevnaker with a population of 4,302. The parish of Jævnaker was established as a municipality on 1 January 1838 (see formannskapsdistrikt). The area of Lunner was separated from the municipality of Jevnaker on 1 January 1898 to form a municipality of its own. From 1 January 2020 the municipality belongs to Viken county, it was Oppland before that.