Year 764 (DCCLXIV) was a leap year starting on Sunday (link will display the full calendar) of the Julian calendar. The denomination 764 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
|Ab urbe condita||1517|
|Balinese saka calendar||685–686|
|Chinese calendar||癸卯年 (Water Rabbit)|
3460 or 3400
— to —
甲辰年 (Wood Dragon)
3461 or 3401
|- Vikram Samvat||820–821|
|- Shaka Samvat||685–686|
|- Kali Yuga||3864–3865|
|Japanese calendar||Tenpyō-hōji 8|
|Minguo calendar||1148 before ROC|
|Seleucid era||1075/1076 AG|
|Thai solar calendar||1306–1307|
890 or 509 or −263
— to —
891 or 510 or −262
- Domenico Monegario is deposed, after Pope Paul I demanded donations from Venice. Monegario is blinded and exiled, and succeeded by Maurizio Galbaio as the 7th doge of Venice. During his reign, Venetian wealth is increased via trade.
- King Offa of Mercia conquers Kent, and brings an end to the rule of kings Ealhmund and Sigered in West Kent. He imposes Mercian overlordship on the kingdom, but allows a local king, Heaberht, to rule there.
- October 14–21 – Fujiwara no Nakamaro Rebellion: A short-lived revolt led by Fujiwara no Nakamaro is suppressed. Emperor Junnin is deposed after a 6-year reign, and forced into exile. Former empress Kōken reassumes the imperial throne of Japan, and takes the name Shōtoku. She appoints her close associate, the priest Dōkyō, prime minister (taishi), running the government with him. Nakamaro is captured and killed with his wife and children.
- According to the historian Theophanes the Confessor, icebergs float past Constantinople from the Black Sea (approximate date).
- Cancor, a Frankish count (possibly of Hesbaye), founds Lorsch Abbey (modern-day Germany).
- Abu Thawr, Muslim scholar (d. 854)
- Al-Hadi, Muslim caliph (d. 786)
- Fujiwara no Nakanari, Japanese nobleman (d. 810)
- Li Jiang, chancellor of the Tang Dynasty (d. 830)
- Tian Hongzheng, general of the Tang Dynasty (d. 821)
- January 17 – Joseph of Freising, German bishop
- Arwa bint Mansur al-Himyari, wife of caliph al-Mansur.
- Abdallah ibn Ali, Muslim general
- Bregowine, archbishop of Canterbury
- Fujiwara no Nakamaro, Japanese statesman (b. 706)
- Stephen the Younger, Byzantine theologian (or 765)
- ^ Sansom, p. 90; excerpt, "... Nakamaro, better known by his later title as the prime minister Oshikatsu, was in high favour with the emperor Junnin but not with the ex-empress Kōken. In a civil disturbance that took place in 764–765, Oshikatsu was captured and killed, while the young emperor was deposed and exiled in 765 and presumably strangled. Kōken reascended the throne as the empress Shōtoku, and her priest Dōkyō was all powerful until she died withous issue in 770."