T-Online is an internet service provider operating in Germany, Hungary, Austria and Switzerland.

T-Online International AG provides broadband Internet access, digital entertainment, and communication services in Germany, France, and Spain. It offers digital subscriber line (DSL) broadband Internet access and voice over Internet protocol based DSL telephony. The company also provides various online services comprising online banking; messaging; online entertainment services that include music downloads, video on demand, online gaming, news, and shopping. In addition, T-Online offers virtual private network, data sharing, and other corporate services to business customers, as well as offers online security products and operates an online information portal. The company was founded in 1995 and is headquartered in Weiterstadt, Germany. As of June 6, 2006, T-Online International AG is a subsidiary of Deutsche Telekom AG.