Clausthal-Zellerfeld is a town in Lower Saxony, Germany. It is located in the southwestern part of the Harz mountains. Its population is approximately 15,000. The town hosts the Clausthal University of Technology. The health resort is located in the Upper Harz at an altitude between 390 and 821 m above sea level.

The Clausthal University of Technology is an institute of technology in Clausthal-Zellerfeld, Lower Saxony, Germany. The small public university is regularly ranked among the Top German universities in engineering by CHE University Rankings. More than 30% of students and 20% of academic staff come from abroad, making it one of the most international universities in Germany. The university is best known for the prominent corporate leaders among its former students. As of 2011, five of the 30 leading companies within the German stock index had alumni of TUC on their management board, with two of them as CEO.