The city of the Leine springs is the largest district of the unified city with about 8700 inhabitants and has an eventful history behind it.

First mentioned in a document in 1227, the village belonged to the Archbishopric of Mainz and Amt Scharfenstein from 1294. In the middle of the 18th century, the village became known for its trade in wool, hair, furs and mustard and grew to become the central traffic and trading point in the Eichsfeld. The rapid development of Leinefeld began in 1867 with the construction of the Leinefeld railroad station. In the 1950s, the convenient location at the road and rail junction led to the decision to build a large cotton mill in Leinefelde. In 1969, the municipality was granted town status. Within three decades, Leinefelde grew from its former population of 2500 to almost 17000. 

The fall of the Berlin Wall and reunification brought the people of Leinefeld not only freedom and the deutschmark, but also high unemployment. The vast majority of the more than 4,000 jobs in the cotton mill were lost in the 1990s. Many of the previously sought-after prefabricated apartments suddenly stood empty. 

Leinefelde lost almost half of its inhabitants, but made the best of its situation with the globally exemplary and award-winning urban redevelopment. Now the town is preparing for another major development step: the State Garden Show 2024.

A famous son of the town is Johann Carl Fuhlrott, discoverer of the Neanderthal man.