Eudoxus was a Greek mathematician from Cnidus, in what is now Turkey. He is famous for his work on calculating the area bounded by a curve as well as the ladder of Eudoxus. It is also believed that some of the work of Euclid of Alexandria is derived from lost work of Eudoxus.

Eudoxus was given a good mathematical education: one of his main teachers was Archytus of Tarentum, who was in turn a follower of Pythagoras. In his education Eudoxus also studied medicine with Philiston of Sicily, and Theomedon. While in Athens Eudoxus also attended discussions with Plato and other philosophers. After this period, presumably on the advice of Plato, Eudoxus spent nearly two years in Egypt studying astronomy. After this Eudoxus felt his basic apprenticeship had been completed, and on his return to Asia Minor he opened up a school that proved very successful. In 386 B.C. Eudoxus and a number of mathematicians from the school visited Athens and Plato. Finally Eudoxus returned to his beloved Cnidus where he was pressed into service as a congressman. This work in running the city still allowed him to continue his other pursuits of mathematics, astronomy, and philosophy. Eventually Eudoxus died in 355 B.C. carrying on the above mentioned work right until the end.

We know that Eudoxus wrote several books covering such topics as mathematics, astronomy, and geography; unfortunately no copies of his work exist. What records we do have of the work of Eudoxus are in the acknowledgements of other, later authors. These later authors include Hipparchus, writing on astronomy, specifically the rising and setting of constellations and planetary movement (Eudoxus postulated a series of concentric spheres holding the planets in their paths). Euclid of Alexandria quoted Eudoxus when writing on relationships between ratios (the foundation of real numbers, which moved away from the Pythagorean love affair with irrational numbers). It is possible that Eudoxus also calculated an accurate length for the solar year, which was a precursor to the later calendar reforms of Julius Caesar. More recent mathematicians have also acknowledged the inspiration that has been given by Eudoxus; these include such people as the early 20th-century mathematician Julius Wilhelm Richard Dedekind.