T-Mobile is a multinational mobile phone operator. It is a subsidiary of Deutsche Telekom and belongs to the FreeMove alliance.

Globally T-Mobile is a group of mobile phone corporate subsidiaries (all under the ownership of Deutsche Telekom) that operate GSM networks in Europe and the United States. The "T" stands for "Telekom." Most subsidiaries of Deutsche Telekom have names beginning with "T-". T-Mobile also has financial stakes in mobile operators in Eastern Europe. Globally, T-Mobile has 109 million subscribers, making it the world's 3rd largest mobile phone service provider, and the 2nd largest multinational, after the U.K's Vodafone.

Deutsche Telekom were recently pipped at the post in acquiring O2 -- thanks to a successful bid from Spain's Telefonica.

T-Mobile is also a sponsor of several sport events in which some carry the company name. For example its own cycling team, the T-Mobile Team, or the Austrian soccer Bundesliga.