Congstar GmbH is a mobile network operator headquartered in Cologne, Germany.

The company is a subsidiary of Telekom Deutschland, and specializes in discount mobile phone service marketed to younger people.

In August 2014, Congstar's services had approximately 3.4 million users.

[1] In December 2019 the brand had over five million customers.

[2] This German corporation or company article is a stub.