Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventions, which include the phonograph, the motion picture camera, and early versions of the electric light bulb, have had a widespread impact on the modern industrialized world. He was one of the first inventors to apply the principles of organized science and teamwork to the process of invention, working with many researchers and employees. He established the first industrial research laboratory.

Edison was raised in the American Midwest. Early in his career he worked as a telegraph operator, which inspired some of his earliest inventions. In 1876, he established his first laboratory facility in Menlo Park, New Jersey, where many of his early inventions were developed. He later established a botanical laboratory in Fort Myers, Florida, in collaboration with businessmen Henry Ford and Harvey S. Firestone, and a laboratory in West Orange, New Jersey, that featured the world's first film studio, the Black Maria. With 1,093 US patents in his name, as well as patents in other countries, Edison is regarded as the most prolific inventor in American history. Edison married twice and fathered six children. He died in 1931 due to complications from diabetes.

Edison was born in 1847 in Milan, Ohio, and grew up in Port Huron, Michigan. Largely self-taught, he developed hearing problems at age 12. He started his career as a news butcher, selling newspapers and later working as a telegraph operator. Edison's entrepreneurial ventures eventually led to the formation of 14 companies, including General Electric. His first patent, granted in 1869, was for an electric vote recorder. Edison later worked with Franklin Leonard Pope, developing a multiplex telegraphic system in 1874.

Edison's Menlo Park Laboratory, established in 1876, was the first industrial research lab focused on constant technological innovation. Funded by the sale of Edison's quadruplex telegraph, the lab led to numerous inventions and developments under Edison's direction. Key inventions include the phonograph, carbon telephone transmitter, and the incandescent light bulb. Edison's lab expanded to occupy two city blocks and was stocked with a vast array of materials for experimentation. Edison's name is registered on 1,093 patents.

Edison developed the first investor-owned electric utility in 1880. He faced competition from alternating current (AC) systems, which could transmit electricity over longer distances and cheaper wires. Edison's direct current (DC) system had limitations in serving areas beyond one mile from the plant. The War of Currents emerged between Edison and AC companies, with Edison publicly claiming AC was dangerous. The war ended in 1892 when Edison's company merged with Thomson-Houston to form General Electric, which competed with Westinghouse for the AC market.

Edison moved to West Orange, New Jersey, and bought a property in Fort Myers, Florida, as a winter retreat. He focused on finding a domestic source of natural rubber, eventually discovering the Goldenrod plant as a viable option. Edison also made significant contributions to other fields, such as telegraphy, motion pictures, and X-ray technology. He designed the first commercially available fluoroscope and invented the tasimeter to measure infrared radiation. In the motion picture industry, he patented the Kinetograph and Kinetoscope, and his film studio produced nearly 1,200 films.

Edison was involved in mining, attempting to extract low-grade iron ore in the United States and discovering nickel and cobalt deposits in Canada. He also developed the nickel-iron battery, although it wasn't very successful. During WWI, Edison produced phenol, a critical material for making phonograph records and other products. Despite engaging in a variety of business ventures, Edison is best known for his work on the electric lightbulb and phonograph. He died in 1931 due to complications from diabetes.

Edison had two wives and six children. He first married Mary Stilwell in 1871, with whom he had three children: Marion Estelle, Thomas Alva Jr., and William Leslie. Mary died in 1884. In 1886, Edison married Mina Miller, and they had three children: Madeleine, Charles, and Theodore Miller. Edison was a freethinker and supported women's suffrage, nonviolence, and monetary reform.

Edison received numerous awards during his lifetime, including an honorary PhD, memberships in prestigious organizations, medals, and distinctions such as the Officer of the Legion of Honour. In recognition of his contributions, various locations, institutions, and awards have been named after him, such as the town of Edison, New Jersey, and the prestigious Edison Medal. Edison's name and achievements have also been commemorated in popular culture, music awards, and the naming of a United States Navy ship.