Daqin (Chinese: 大秦; pinyin: Dàqín; Wade–Giles: Ta⁴-ch'in²; alternative transliterations include Tachin, Tai-Ch'in) is the ancient Chinese name for the Roman Empire or, depending on context, the Near East, especially Syria. It literally means "great Qin"; Qin (Chinese: 秦; pinyin: Qín; Wade–Giles: Ch'in²) being the name of the founding dynasty of the Chinese Empire. Historian John Foster defined it as "the Roman Empire, or rather that part of it which alone was known to the Chinese, Syria". Its basic facets such as laws, customs, dress, and currency were explained in Chinese sources. Its medieval incarnation was described in histories during the Tang dynasty (618–907 AD) onwards as Fulin (Chinese: 拂菻; pinyin: Fúlǐn), which Friedrich Hirth and other scholars have identified as the Byzantine Empire. Daqin was also commonly associated with the Syriac-speaking Nestorian Christians who lived in China during the Tang dynasty.

Chinese sources describe several ancient Roman embassies arriving in China, beginning in 166 AD and lasting into the 3rd century. These early embassies were said to arrive by a maritime route via the South China Sea in the Chinese province of Jiaozhi (now northern Vietnam). Archaeological evidence such as Roman coins points to the presence of Roman commercial activity in Southeast Asia. Later recorded embassies arriving from the Byzantine Empire, lasting from the 7th to 11th centuries, ostensibly took an overland route following the Silk Road, alongside other Europeans in Medieval China. Byzantine Greeks are recorded as being present in the court of Kublai Khan (1260–1294), the Mongol ruler of the Yuan dynasty in Khanbaliq (Beijing), while the Hongwu Emperor (r. 1368–1398), founder of the Ming dynasty, sent a letter of correspondence to Byzantine emperor John V Palaiologos.