The Telephone Cases were a series of U.S. court cases in the 1870s and 1880s related to the invention of the telephone, which culminated in the 1888 decision of the United States Supreme Court upholding the priority of the patents belonging to Alexander Graham Bell. Those telephone patents were relied on by the American Bell Telephone Company and the Bell System –although they had also acquired critical microphone patents from Emile Berliner.

The objector (or plaintiff) in the notable Supreme Court case was initially the Western Union telegraph company, which was at the time a far larger and better financed competitor than American Bell Telephone. Western Union advocated several more recent patent claims of Daniel Drawbaugh, Elisha Gray, Antonio Meucci and Philip Reis in a bid to invalidate Alexander Graham Bell's master and subsidiary telephone patents dating back to March 1876. Had Western Union succeeded it would have immediately destroyed the Bell Telephone Company and then Western Union stood to become the world's largest telecommunications monopoly in Bell's place.