International Data Corporation is an American provider of market intelligence, advisory services, and events for the information technology, telecommunications, and consumer technology markets. Founded in 1964, IDC is a wholly owned subsidiary of International Data Group, a media, data and marketing services company.

• IDC was founded by Patrick Joseph McGovern in Massachusetts, in 1964. At the outset, the company produced a computer installation data base (based on a customer list purloined from IBM), and published a newsletter, "EDP Industry and Market Report" (modeled on "ADP Newsletter", which was published by The Diebold Group). Companies such as RCA, Univac, Xerox, and Burroughs paid IDC for use of the data base. During this time, Mcgovern continued to work as a writer for "Computers and Automation" magazine, the first computer magazine, published by Edmund Berkeley.
• McGovern frequently described his having sold his old car for $5,000, to fund the startup of IDC. By its third year, the company had an income of $154,996. A modest net profit of $2,961. McGovern was considering liquidating the company when he hit on the idea of launching Computerworld in 1967, which was a continuation of the monthly newsletter, published weekly instead of monthly, in a different format, with advertising, which became a cornerstone of IDG's subsequent publishing arm.
• Subsequently, failing to wrest control of "Computers and Automation" magazine from his friend and mentor, Ed Berkeley, he left Berkeley and founded "PC World".
• In 2017, IDC and IDG were acquired by China Oceanwide Holdings Group.