Lachendorf (West Low German: Lachendörp) is a municipality in the district of Celle, in Lower Saxony, Germany.

It is situated approximately 10 km east of Celle.

In older records Lachendorf is mentioned under the name of Lachtendorp, meaning village at the river Lachte.

In 1538 Ernest I, Duke of Brunswick-Lüneburg chose it as a proper place for a paper mill, which marks the beginning of settlement and commercial development.

In 1845 the paper mill was extended to a factory, creating a remarkable amount of workspace in this agricultural region.