Siemens cellular telephones were mobile phones, produced by Siemens AG.

In 2005 the Taiwanese company BenQ acquired the financially bleeding mobile phone subsidiary from Siemens and gained the exclusive right to use Siemens trademark for 5 years. Before transferring the mobile phone subsidiary to BenQ, Siemens invested 250 million euros and wrote down assets amounting to 100 million euros [1]. Siemens also acquired a 2.5% stake in BenQ for 50 million euros. BenQ subsequently released mobile phones under the BenQ-Siemens brand, from its German unit.
In 2006, this German unit filed for bankruptcy