The earliest known world maps date to classical antiquity, the oldest examples of the 6th to 5th centuries BCE still based on the flat Earth paradigm. World maps assuming a spherical Earth first appear in the Hellenistic period. The developments of Greek geography during this time, notably by Eratosthenes and Posidonius culminated in the Roman era, with Ptolemy's world map (2nd century CE), which would remain authoritative throughout the Middle Ages. Since Ptolemy, knowledge of the approximate size of the Earth allowed cartographers to estimate the extent of their geographical knowledge, and to indicate parts of the planet known to exist but not yet explored as terra incognita.

With the Age of Discovery, during the 15th to 18th centuries, world maps became increasingly accurate; exploration of Antarctica, Australia, and the interior of Africa by western mapmakers was left to the 19th and early 20th century.

The Saint-Bélec slab discovered in 1900 by Paul du Châtellier, in Finistère, France, is dated to between 1900 BCE and 1640 BCE. A recent analysis, published in the Bulletin of the French Prehistoric Society, has shown that the slab is a three-dimensional representation of the River Odet valley in Finistère, France. This would make the Saint-Bélec slab the oldest known map of a territory in the world. According to the authors, the map probably was not used for navigation, but rather to show the political power and territorial extent of a local ruler's domain of the early Bronze Age.

A Babylonian world map, known as the Imago Mundi, is commonly dated to the 6th century BCE. The map as reconstructed by Eckhard Unger shows Babylon on the Euphrates, surrounded by a circular landmass including Assyria, Urartu (Armenia) and several cities, in turn surrounded by a "bitter river" (Oceanus), with eight outlying regions (nagu) arranged around it in the shape of triangles, so as to form a star. The accompanying text mentions a distance of seven beru between the outlying regions. The descriptions of five of them have survived:

Anaximander (died c. 546 BCE) is credited with having created one of the first maps of the world, which was circular in form and showed the known lands of the world grouped around the Aegean Sea at the center. This was all surrounded by the ocean.

Hecataeus of Miletus is credited with a work entitled Periodos Ges ("Travels round the Earth" or "World Survey"), in two books each organized in the manner of a periplus, a point-to-point coastal survey. One, on Europe, is essentially a periplus of the Mediterranean, describing each region in turn, reaching as far north as Scythia. The other book, on Asia, is arranged similarly to the Periplus of the Erythraean Sea of which a version of the 1st century CE survives. Hecataeus described the countries and inhabitants of the known world, the account of Egypt being particularly comprehensive; the descriptive matter was accompanied by a map, based upon Anaximander's map of the Earth, which he corrected and enlarged. The work only survives in some 374 fragments, by far the majority being quoted in the geographical lexicon the Ethnica, compiled by Stephanus of Byzantium.

Eratosthenes (276–194 BCE) drew an improved world map, incorporating information from the campaigns of Alexander the Great and his successors. Asia became wider, reflecting the new understanding of the actual size of the continent. Eratosthenes was also the first geographer to incorporate parallels and meridians within his cartographic depictions, attesting to his understanding of the spherical nature of the Earth.

Posidonius (or Poseidonius) of Apameia (c. 135–51 BCE) was a Greek Stoic philosopher who traveled throughout the Roman world and beyond and was a celebrated polymath throughout the Greco-Roman world, like Aristotle and Eratosthenes. His work "about the ocean and the adjacent areas" was a general geographical discussion, showing how all the forces had an effect on each other and applied also to human life. He measured the Earth's circumference by reference to the position of the star Canopus. His measure of 240,000 stadia translates to 24,000 miles (39,000 km), close to the actual circumference of 24,901 miles (40,074 km). He was informed in his approach by Eratosthenes, who a century earlier used the elevation of the Sun at different latitudes. Both men's figures for the Earth's circumference were uncannily accurate, aided in each case by mutually compensating errors in measurement. However, the version of Posidonius' calculation popularised by Strabo was revised by correcting the distance between Rhodes and Alexandria to 3,750 stadia, resulting in a circumference of 180,000 stadia, or 18,000 miles (29,000 km). Ptolemy discussed and favored this revised figure of Posidonius over Eratosthenes in his Geographia, and during the Middle Ages scholars divided into two camps regarding the circumference of the Earth, one side identifying with Eratosthenes' calculation and the other with Posidonius' 180,000 stadion measure, which is now known to be about 33% too low. This was the number used by Christopher Columbus to underestimate the distance to India as 70,000 stades.