VDO (Vereinigte DEUTA (Duetsche Tachometerwerke GmbH) OTA (OTA Apparate GmbH)) was a manufacturer of information and cockpit systems, navigation, telematics, communication and audio systems and control and fuel systems.

The company was founded by Adolf Schindling at the end of the 1920s in Frankfurt, Germany by joining DEUTA and OTA. The company made tachometers and instrument clusters for passenger cars and commercial vehicles.

In 1991 the company was bought by Atecs Mannesmann . In 1999 Mannesmann was itself bought by Vodafone Airtouch and VDO was put up for sale. In 2000 the company was bought by Siemens Automotive and the companies merged under the name Siemens VDO.