DDR is a three-letter abbreviation with multiple meanings, including:

• Deutsche Demokratische Republik, the former German Democratic Republic also known as East Germany.
• Dance Dance Revolution video game series
• Double data rate, in computing, is a type of computer bus; one common application of this is DDR SDRAM.
• Disarmament, Demobilization and Reintegration - activities designed to facilitate disbanding military fighters and easing their transition back into society. For example: Afghan Disarmament, Demobilization and Reintegration Program
• Dial-on-demand routing
• Distributed dynamic routing