Aarhus is the second-largest city in Denmark and the seat of Aarhus municipality. It is located on the eastern shore of Jutland in the Kattegat sea and approximately 187 kilometres (116 mi) northwest of Copenhagen.

The largest city in Jutland, Aarhus anchors the Central Denmark Region and the statistical region Landsdel Østjylland (LØ) (Lit. Province East Jutland). The LØ is the most populous statistical region in Denmark with an estimated population of 903 974 (as of 1 January 2021). Aarhus Municipality defines the greater Aarhus area as itself and 8 adjacent municipalities totalling 952,824 inhabitants (as of 1 January 2021) which is roughly analogous to the municipal and commercial collaboration Business Region Aarhus. The city proper, with an estimated population of 280,534 inhabitants (as of 2020), ranks as the 2nd-largest city in Denmark.

Aarhus was founded in the 8th century as a Viking fort on the northern shores of a fjord by the mouth of Aarhus River. Situated on intersecting trade routes in the Danish Straits it grew from a primarily military installation into a trade hub and in 1441 it was granted Market town privileges. Buttressed by regional trade and as the seat of a bishopric population remained stable during a politically unstable period lasting until the 19th century. The industrial revolution became an inflection point as industry drove rapid population growth outpacing regional rivals. In 1934 the first university in Jutland was founded in Aarhus and today it is a university city and the largest centre for trade, services, industry, and tourism in Jutland.

Designated as a "Sufficiency" global city by the Globalization and World Cities Research Network, the city's major cultural institutions include Den Gamle By, ARoS Aarhus Kunstmuseum, Moesgård Museum, Kvindemuseet, Musikhuset and Aarhus Theatre. Known as Smilets By (Lit. City of Smiles) it is the Danish city with the youngest and fastest growing demographics and home to Scandinavia's largest university, Aarhus University. Commercially the city is the principal container port in the country and major Danish companies are headquartered there such as Vestas, Arla Foods, Salling Group and Jysk.