Katlenburg-Lindau is a municipality located in the district of Northeim within the state of Lower Saxony, Germany. It is situated approximately 10 km southeast of Northeim and 20 km northeast of Göttingen.
The municipality was formed on March 1, 1974, through the merger of several formerly independent communities: Katlenburg-Duhm, Gillersheim, Berka, Elvershausen, Wachenhausen, Suterode, and Lindau. While most of these communities were originally part of Landkreis Northeim, Lindau previously belonged to Landkreis Duderstadt.
The area is notable for having hosted the Max Planck Institute for Solar System Research (formerly known as the Max-Planck-Institut für Aeronomie) in Lindau from 1946 until its relocation to Göttingen in 2014.