Laatzen is a town in the district of Hanover, in Lower Saxony, Germany. It is situated directly south of Hanover.
In 1964, the municipalities of Laatzen (nowadays about 22,000 inhabitants) and Grasdorf (3,500 inh.) were merged into the town of Laatzen. In 1974 the towns of Rethen/Leine (8,100 inh.), Gleidingen (4,300 inh.) and Ingeln-Oesselse (3,700 inh.) were joined to the town.