The Joachimsthal Gymnasium (German Joachimsthalsches or Joachimsthaler Gymnasium), was a princely high school (German Fürstenschule) for gifted boys, founded in 1607 in Joachimsthal, Brandenburg.

The school in Templin was closed in 1956, while the area was part of East Germany, and its buildings were used for other purposes until 1996.

In 2013, the initiative Joachimsthalsches Gymnasium Templin was created, with the aim of converting the traditional school buildings at Templin into a new internationally oriented boarding school.

On 6 December 2018, the Board of Governors of the European Schools, an NGO which has representatives of the Education Ministers of the EU Member States, decided to begin the accreditation process for a "European School Templin" (EST).

Work on the renovation of the buildings is now under way, and the opening of the new school is planned for 2023.