The Old World consists of those parts of Earth known to Europeans before the voyages of Christopher Columbus: Europe, Asia, and Africa (collectively known as Africa-Eurasia) and the surrounding islands. The term is in distinction from the New World, meaning the Americas.

Although the interiors of Asia and Africa were not well known to Europeans at the time, their existence was known, as far as Japan and South Africa, so they are considered Old World. Australia and Antarctica are neither definitely Old World nor definitely New World, since the terms "Old World" and "New World" predate their discovery by Europeans.

In biological usage, Old World organisms are those found in Eurasia, Africa and Australasia, and New World organisms are those found in the Americas. The placement of Australasia in the Old World for biological purposes reflects the general pattern of dispersion and radiation of species in the course of evolution.

Old World wines is also used to refer to traditional wine-growing regions and the wines produced there, in contrast to New World wines.