Esslingen am Neckar is a city in the Stuttgart Region of Baden-Württemberg in southern Germany, seat of the District of Esslingen. Within Baden-Württemberg it is the 10th largest city.

It is located on the river Neckar, about 14 kilometres (9 miles) southeast of Stuttgart city center. The regions surrounding the city of Esslingen are also mostly developed.

Esslingen is first mentioned in written records in the 8th century. From 1181, it was a Free Imperial City. In 1803, the city lost its independence and was incorporated into the Duchy of Württemberg. Industrialization in the 19th century led to economic growth and significantly shaped the city’s development.

There is archaeological evidence that what is now the city of Esslingen was settled since the Neolithic period. Traces of human settlement found at the site of the city church date back to around 1000 B.C.

In the 1st century AD the Esslingen region became part of the Roman Empire. During this period a Roman warehouse was located in the area of Oberesslingen. The nearest major Roman settlements and garrisons were at Cannstatt and Köngen.

There are no known archaeological finds from the early period of Alemannic rule in the area, although such evidence does exist on the nearby Filder uplands. Finds from the district of Rüdern, however, point to a richly furnished grave with eastern influences, including, for example, a set of three-winged spearheads. The place-name ending "-ingen" indicates a settlement associated with a kinship group led by a man named Azzilo, Hezzilo, or Hetsilo, who likely was a landlord and family patriarch. The city's name, therefore, originally meant "the people and land of Azzilo." This name is first documented in 856 as "Ezlinga" and again in 866 as "Hetsilinga", forms that eventually evolved into the modern name Esslingen.

In the 6th century, the Alemanni were subjugated by the Merovingians under king Clovis I. But they still took over administrative tasks and formed a Duchy in Francia. In the 8th century they tried to become sovereign again. But the attempt failed near Cannstatt. The end of the Alemannian duchy was marked with the Council of Cannstatt.

In an excavation by Günter Fehring, the remains of the Vitalis-Cella under the church St. Dionysius were uncovered. Proof of settlement dates back to the late Merovingian period. Even older are the single row graves in Oberesslingen and Sirnau.

Esslingen was first mentioned in 777 in the last will of Abbot Fulrad from Saint-Denis (near Paris), the chaplain of Pippin and Charlemagne. He bequeathed the sixth cell upon the river Neckar that he had received from an Alemannic nobleman by the name of "Hafti" to his monastery, Saint-Denis. He also brought the bones of Saint Vitalis to Esslingen, which made it a destination for pilgrims and led to its growth.

Around 800 Esslingen became a market town, its market rights being certified in 866. In 949-953 it was a possession of Liudolf, Duke of Swabia. Esslingen received city rights in 1229 under Emperor Frederick II. During the same period the still-extant Neckar bridge was built, making Esslingen a major center for trade on the route between Italy, Switzerland, and northern Germany. Taxes provided by the bridge and market led to further growth of the town, as did the export of the highly regarded wines from the region.

The period between the 13th century and 16th century saw many conflicts between the Free Imperial City and the Counts of Württemberg (later Duchy of Württemberg). About half the population died in the Thirty Years' War between 1618 and 1648 through famine or epidemics. Esslingen lost its independence as an Imperial city during the Napoleonic era in 1802–1803, becoming part of the Duchy of Württemberg.

The city had a defensive wall, part of which remains, including a landmark "fat tower" (Der Dicke Turm) set on the hill and vineyards above the city. A marketplace plaza at the center of the city is ringed by characteristic half-timbered buildings. A landmark "old city hall" (Altes Rathaus) stands nearby.

The beginning of the 19th century was characterized by industrialization. Glove manufacturing, food processing, textiles, and metal working were early industries in Esslingen. On 20 November 1845 the first train ran from Cannstatt to Esslingen station.

Esslingen was occupied by U.S. troops starting in April 1945, at the very end of World War II. During the war the city suffered very little damage, and it was peaceably surrendered to the approaching allied forces, thus the medieval character of its city center has been mostly preserved.

After the Second World War about 47,000 people moved to Esslingen, mostly refugees and displaced persons from East Germany. Housing developments in Oberesslingen and Zollberg were created to overcome the shortage of housing.

In 1973 Nürtingen district was merged with Esslingen am Neckar, making Esslingen the seat of a much enlarged district.