The Qin Dynasty (Chinese: 秦朝; pinyin: Qín Cháo; Wade-Giles: Ch'in Ch'ao; IPA: [tɕʰǐn tʂʰɑ̌ʊ̯]) was the ruling Chinese dynasty between 221 and 206 BC. The Qin state derived its name from its heartland of Qin, in modern-day Shaanxi. The Qin's strength had been consolidated by Lord Shang Yang during the Warring States Period, in the 4th century BC. In the early third century BC, the Qin accomplished a series of swift conquests; the state subjugated the Chu, remnants of the Zhou Dynasty, and various other states to gain undisputed control of China.

During its reign over China, the Qin Dynasty enjoyed increased trade, agriculture, and military security. This was due to the abolition of landowning lords, to whom peasants had formerly held allegiance. The central government now had direct control of the masses, giving it access to a much larger workforce. This allowed for the construction of ambitious projects, such as a wall on the northern border, now known as the Great Wall of China. The Qin Dynasty also introduced several reforms; weights and measures were standardized, use of currency started, and a better system of writing was established. An attempt to purge all traces of the old dynasties led to the infamous burning of books and burying of scholars incident, which has been criticised greatly by subsequent scholars. The Qin's military was also revolutionary in that it used the most recently developed weaponry, transportation, and tactics, though the government was heavy-handed and bureaucratic.

Despite its military strength, the Qin Dynasty did not last long. When the first emperor died in 210 BC, his son was placed on the throne by two of the previous emperor's advisers, in an attempt to influence and control the administration of the entire country through him. They squabbled among themselves, however, which resulted in both their deaths and that of the second Qin emperor. Popular revolt broke out a few years later, and the weakened empire soon fell to a Chu lieutenant, who went on to found the Han Dynasty. Despite its rapid end, the Qin Dynasty influenced future Chinese regimes, particularly the Han, and from it is derived the modern name for China.