Essen is a city in the central part of the Ruhr area in North Rhine-Westphalia, Germany. Located on the River Ruhr, its population of approximately 567,000 (as of 31 December 2012) makes it the 9th-largest city in Germany. For the year 2010, Essen was the European Capital of Culture on behalf of the whole Ruhr area.

Founded around 845 and historically linked to the centuries-old Krupp family iron works, Essen was one of Germany's most important coal and steel centres until the 1970s and attracted workers from all over the country; it was the 5th-largest city in Germany between 1929 and 1988, peaking at over 730,000 inhabitants in 1962. The city has since developed a strong tertiary sector of the economy, so it is sometimes called "desk of the Ruhr area". Essen is home to 13 of the 100 largest German corporations and seat to several of the region's authorities.

In 1958, the city was chosen to serve as the seat to a Roman Catholic diocese (often referred to as Ruhrbistum or diocese of the Ruhr). In early 2003, the universities of Essen and the nearby city of Duisburg (both established in 1972) were merged into the University of Duisburg-Essen with campuses in both cities and a university hospital in Essen.

In German-speaking countries, the name of the city Essen often causes confusion as to its origins, because it is commonly known as the German infinitive of the verb for the act of eating, and/or the German noun for food. Although scholars still dispute the interpretation of the name, there remain a few noteworthy interpretations. The oldest known form of the city's name is Astnide, which changed to Essen by way of forms such as Astnidum, Assinde, Essendia and Esnede. The name Astnide may have referred either to a region where many ash trees were found or to a region in the East (of the Frankish Empire). The Old High German word for fireplace, Esse, is also commonly mentioned due to the industrial history of the city, but is highly unlikely since the old forms of the city name originate from times before industrialization.

Essen is located in the centre of the Ruhr area, one of the largest urban areas in Europe (see also: megalopolis), comprising eleven independent cities and four districts with some 5.3 million inhabitants. The city limits of Essen itself are 87 km (54 mi) long and border ten cities, five independent and five kreisangehörig (i.e., belonging to a district), with a total population of approximately 1.4 million.

The city extends over 21 km (13 mi) from north to south and 17 km (11 mi) from west to east, mainly north of the River Ruhr, which forms the Lake Baldeney reservoir in the boroughs of Fischlaken, Kupferdreh, Heisingen and Werden. The lake, a popular recreational area, dates from 1931 to 1933, when some thousands of unemployed coal miners dredged it with primitive tools . Generally, large areas south of the River Ruhr (including the suburbs of Schuir and Kettwig) are quite green and are often quoted as examples of rural structures in the otherwise relatively densely populated central Ruhr area.

The lowest point can be found in the northern borough of Karnap at 26.5 m (86.9 ft), the highest point in the borough of Heidhausen 202.5 m (664 ft). The average elevation is 116 m (381 ft).