The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team of engineers and designers at International Business Machines (IBM), directed by William C. Lowe and Philip Don Estridge in Boca Raton, Florida.

Powered by an x86-architecture Intel 8088 processor, the machine was based on open architecture and third-party peripherals. Over time, expansion cards and software technology increased to support it. The PC had a substantial influence on the personal computer market; the specifications of the IBM PC became one of the most popular computer design standards in the world. The only significant competition it faced from a non-compatible platform throughout the 1980s was from Apple's Macintosh product line, as well as consumer-grade platforms created by companies like Commodore and Atari. Most present-day personal computers share architectural features in common with the original IBM PC, including the Intel-based Mac computers manufactured from 2006 to 2022.

Prior to the 1980s, IBM had largely been known as a provider of business computer systems. As the 1980s opened, their market share in the growing minicomputer market failed to keep up with competitors, while other manufacturers were beginning to see impressive profits in the microcomputer space. The market for personal computers was dominated at the time by Tandy, Commodore, and Apple, whose machines sold for several hundred dollars each and had become very popular. The microcomputer market was large enough for IBM's attention, with $15 billion in sales by 1979 and projected annual growth of more than 40% during the early 1980s. Other large technology companies had entered it, such as Hewlett-Packard, Texas Instruments, and Data General, and some large IBM customers were buying Apples.

As early as 1980 there were rumors of IBM developing a personal computer, possibly a miniaturized version of the IBM System/370, and Matsushita acknowledged publicly that it had discussed with IBM the possibility of manufacturing a personal computer in partnership, although this project was abandoned. The public responded to these rumors with skepticism, owing to IBM's tendency towards slow-moving, bureaucratic business practices tailored towards the production of large, sophisticated and expensive business systems. As with other large computer companies, its new products typically required about four to five years for development, and a well publicized quote from an industry analyst was, "IBM bringing out a personal computer would be like teaching an elephant to tap dance."

IBM had previously produced microcomputers, such as 1975's IBM 5100, but targeted them towards businesses; the 5100 had a price tag as high as $20,000. Their entry into the home computer market needed to be competitively priced.

In the summer of 1979, Ron Mion, IBM’s Senior Business Trends Advisor for entry-level systems, proposed a plan for IBM to enter the emerging microcomputer market. At that time, the likes of Apple and Tandy were starting to encroach on the small-business marketplace that IBM intended to dominate. Mion believed that that market would grow significantly and that IBM should aggressively pursue it. However, he felt that they wouldn’t be successful unless IBM departed from its long-standing business model.

Mion’s plan called for three major departures from how IBM traditionally did business. Mion felt that, if IBM wanted to compete in the microcomputer market, it would need to:

That plan made its way up the chain of command but was ultimately rejected in the fall. The top IBM executives reaffirmed that all “IBM” computers, and their major components, must be developed, manufactured, sold, and serviced by IBM.