Gaius Julius Verus Maximinus "Thrax" ("the Thracian"; c.173 238) was Roman emperor from 235 to 238.

His father was an accountant in the governor's office and sprang from ancestors who were Carpi (a Dacian tribe), a people whom Diocletian would eventually drive from their ancient abode (in Dacia) and transfer to Pannonia. Maximinus was the commander of the Legio IV Italica when Severus Alexander was assassinated by his own troops in 235. The Pannonian army then elected Maximinus emperor.In 238 (which came to be known as the Year of the Six Emperors), a senatorial revolt broke out, leading to the successive proclamation of Gordian I, Gordian II, Pupienus, Balbinus and Gordian III as emperors in opposition to Maximinus. Maximinus advanced on Rome to put down the revolt, but was halted at Aquileia, where he was assassinated by disaffected elements of the Legio II Parthica.

Maximinus is described by several ancient sources, though none are contemporary except Herodian's Roman History. He was a so-called barracks emperor of the 3rd century; his rule is often considered to mark the beginning of the Crisis of the Third Century. Maximinus was the first emperor who hailed neither from the senatorial class nor from the equestrian class.

The Year of the Six Emperors was the year AD 238, during which six men made claims to be emperors of Rome. This was an early symptom of what historians now call the Crisis of the Third Century, also known as Military Anarchy or the Imperial Crisis (AD 235–284), a period in which the Roman Empire nearly collapsed under the combined pressures of barbarian invasions and migrations into the Roman territory, civil wars, peasant rebellions, political instability (with multiple usurpers competing for power), Roman reliance on (and growing influence of) barbarian mercenaries known as foederati and commanders nominally working for Rome (but increasingly independent), the devastating social and economic effects of the plague, debasement of currency, and economic depression. The crisis ended with the ascension of Diocletian and his implementation of reforms in 284.