Sennheiser electronic GmbH & Co. KG KG is a privately owned German audio company specialized in the design and production of a wide range of high precision audio products including microphones, headphones, monitoring systems, aviation headphones for personal, professional and business applications.

The company was founded in 1945, only a few weeks after World War II, by Professor Fritz Sennheiser (1912-2010) and seven engineers at Hanover University in a laboratory called Laboratorium Wennebostel (short for "Lab W "). The lab was named after Wennebostel in the municipality of Wedemark, where it was moved because of the war. The first product produced was a voltmeter. Lab W began to build microphones in 1946 (DM1), continuing their successful development in 1947 with the DM2.

By 1955, the company now has 250 employees and produces a diverse range of products including, but not limited to: geophysical equipment, microphones with sound insulation (DM4), microphone transformers, mixers and miniature magnetic headphones. "Lab W" was renamed "Sennheiser electronic" in 1958.

In 1968 Sennheiser released the world's first open headset (HD 414) to launch high-end product history.
Introducing an open headset has a great deal of impact on the market as they can reproduce a more natural sound. Consumer interest in HD 414 is enormous and by the end of 1969 more than 100,000 units have been sold. To this day, it is still the bestselling headphone of all time with over 10 million units sold.

In 1980, the company entered the aviation market by equipping Lufthansa with aviation headphones.

Sennheiser began production of modern wireless microphones in 1982. In the same year, founder Fritz Sennheiser handed over the company's management to his son, Jörg Sennheiser.
In 1987, Prof. Dr. Fritz Senheiser received an academic award for his MKH 816 shotgun microphone. In the same year, the company was actively developing NoiseGard sound insulation for Lufthansa.

In 1991, Georg Neumann GmbH, Berlin, which is building studio microphones, became part of Sennheiser.

In 1996, Sennheiser received the "Emmy" Award for innovative developments in wireless RF technology. In the same year, Sennheiser became a private limited liability company (GmbH and Co. KG). Prof. Dr. Fritz Senheiser died in 2010 at the age of 98.

In 2011, Daniel Sennheiser and Andreas Sennheiser, grandchildren of the founder of the company, joined the board, joining the Management Board on 1 July 2013, assuming overall responsibility as Chief Executive Officers responsible for Sennheiser electronic GmbH & Co. KG.

In October 2013 at the 65th Primetime Emmy®Engineering Awards ceremony in Hollywood, Sennheiser performed the prestigious award of Phil T. Farnsworth. The prize distinguishes an agency, a company, or an institution for having a grand contribution on television technology and engineering over a long period of time.

In May 2014, Sennheiser founds a new competence center for innovative streaming solutions, Sennheiser Streaming Technology GmbH (SST).

At the end of 2017, Sennheiser already employs 2,833 employees (52%) in Germany and (48%) abroad, and the annual turnover reaches €667.7 million.

In 2018, the Sennheiser Group generated turnover totaling €710.7 million.