The Free World is a Cold War-era term used by non-communist nations to describe themselves. The term was used to contrast the supposed greater freedom enjoyed by citizens of non-communist countries that called themselves democratic, such as the United States and Western Europe, with the Soviet Union and its East European allies. The usage of this term, however, generally does not take into account the many other non-communist states allied with the "Free World" during the Cold War, most notably in South America, Asia and Africa, many of which have been criticised as repressive and dictatorial.

Because of America's prominent role in the Cold War, the president of the United States was often dubbed the "leader of the Free World", particularly in the United States itself.

Although the term had its vogue during the Cold War, it had been used before, at least occasionally, to refer to the nations fighting Germany in the Second World War. Such use may have included the Soviet Union by implication.

One of the earliest uses of the term Free World as a politically significant term occurs in Frank Capra's World War II propaganda film series Why We Fight. In the first film of that series, the "free world" is dramatically contrasted with the "slave world," in the words of the narration. The film depicts the free world as the Western Hemisphere, led by the United States and Western Europe, and the slave world as the Eastern Hemisphere, dominated by Nazi Germany and the Japanese Empire. The films portray the Soviet Union as an ally of the "Free World", which it was, from the perspective of nations fighting Germany in World War II.

Richard Stallman and the free software movement use the term Free World to describe the set of software, people, commercial/non-profit companies, that adhere to the 4 basic freedoms of free software.

So they for example speak of the Free World (note the capital letters) when they refer to a GNU/Linux distribution composed only of free software and they say that for example some free application that use non-free libraries can't be run in a Free World, since in a Free World these non-free libraries don't exist. Debian GNU/Linux (the main distribution of Debian) is a self-sufficient system composed of Free Software, but since the Debian Project also distributes some non-free software, it's not touted by RMS et al.

In a broader sense, lawyers for example are said to live in a Free World, because they have the freedom to study, modify and freely redistribute legal knowledge, decisions and strategies.