Between 26 July and 21 August 2023, 10 human infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant BA.2.86 were detected in Denmark. On 17 August, the World Health Organization (WHO) classified BA.2.86 as a variant under monitoring. The new variant, with a range of new spike (S) gene mutations, was quickly detected in several countries, including Israel, South Africa, the United Kingdom and the United States (US), suggesting international transmission. Here, we report on the first cases detected and surveillance data from Denmark, including epidemiological data and molecular characteristics of the variant.