International Business Machines Corporation (IBM) is an American multinational information technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the Computing-Tabulating-Recording Company (CTR) and was renamed "International Business Machines" in 1924.

IBM produces and sells computer hardware, middleware and software, and provides hosting and consulting services in areas ranging from mainframe computers to nanotechnology. IBM is also a major research organization, holding the record for most U.S. patents generated by a business (as of 2019) for 26 consecutive years. Inventions by IBM include the automated teller machine (ATM), the floppy disk, the hard disk drive, the magnetic stripe card, the relational database, the SQL programming language, the UPC barcode, and dynamic random-access memory (DRAM). The IBM mainframe, exemplified by the System/360, was the dominant computing platform during the 1960s and 1970s.

IBM has continually shifted business operations by focusing on higher-value, more profitable markets. This includes spinning off printer manufacturer Lexmark in 1991 and the sale of personal computer (ThinkPad/ThinkCentre) and x86-based server businesses to Lenovo (in 2005 and 2014, respectively), and acquiring companies such as PwC Consulting (2002), SPSS (2009), The Weather Company (2016), and Red Hat (agreement announced in October 2018, actual acquisition to be in the second half of 2019). Also in 2014, IBM announced that it would go "fabless", continuing to design semiconductors, but offloading manufacturing to GlobalFoundries.

Nicknamed Big Blue, IBM is one of 30 companies included in the Dow Jones Industrial Average and one of the world's largest employers, with (as of 2017) over 380,000 employees, known as "IBMers". At least 70% of IBMers are based outside the United States, and the country with the largest number of IBMers is India.[6] IBM employees have been awarded five Nobel Prizes, six Turing Awards, ten National Medals of Technology (USA) and five National Medals of Science (USA).