ADC Telecommunications, Inc. was a communications company in Eden Prairie, Minnesota, a southwest suburb of Minneapolis. It was acquired by TE Connectivity (Tyco Electronics) in December 2010 and ceased to exist as a separate entity. ADC products were sold by CommScope after it acquired the Broadband Network Solutions business unit (including ADC) from TE Connectivity in August 2015.

ADC Telecommunications was founded in 1935 in Minneapolis, Minnesota, by Ralph Allison and Walter Lehnert.

During their first year in business, ADC built hearing aids and audiometers—a machine used for evaluating hearing acuity. Initially the audiometers were built for Maico, but in 1945 ADC began building audiometers under its own name. Additionally, by 1942, the company had designed a sophisticated audio system for the University of Minnesota, and the resulting jacks, plugs, patch cords and jackfields became the cornerstones for ADC's later entry into telecommunications.

In 1949, ADC sold its audiometer product line and Ralph Allison left the company to form a new business in California. With Walter Lehnert remaining as president of the company, ADC diversified and focused its efforts in the area of transformers and filters for power lines, military electronics, telephone jacks and plugs.

In 1961, ADC merged with Magnetic Controls Company, a manufacturer of power supplies and magnetic amplifiers with strong ties to the U.S. space program. The resulting company, ADC Magnetic Controls, had a decade of mixed success. Although transformer sales boomed during the 1960s, other new product initiatives failed to materialize. Perhaps the most significant product innovation during this period was the bantam jack, a miniaturized component that eventually became the standard for telephone circuit access and patching. Building on its growing sales of jacks and plugs in the early 1970s, ADC introduced prewired, connectorized jackfields, wired assemblies and test equipment for telephone operating companies. By 1976, ADC had become the largest independent supplier of test boards in the United States.

ADC grew in 1983, when AT&T was ordered to deregulate by the federal government. By establishing the seven Regional Bell Operating Company (RBOC) carriers as independent entities, the U.S. market for telecommunications expanded by 90 percent. ADC became a supplier for the RBOCs.

ADC embarked on some acquisitions in the early 1990s, attempting to move "up the stack" in the datacom field by acquiring companies that manufactured datacom equipment. However, their ability to find synergies between these companies proved limited and eventually ADC was forced to move away from a hardware-only strategy, broadening out into software. This effort resulted in limited success as well, and happening about the same time as the dot-com bubble burst, caused ADC stock to plummet.

ADC Telecommunications was acquired by Tyco Electronics in July 2010 for a reported $12.75 per share in cash, or an enterprise value of approximately $1.25 billion.