|703 by topic|
|Ab urbe condita||1456|
|Balinese saka calendar||624–625|
|Chinese calendar||壬寅年 (Water Tiger)|
3399 or 3339
— to —
癸卯年 (Water Rabbit)
3400 or 3340
|- Vikram Samvat||759–760|
|- Shaka Samvat||624–625|
|- Kali Yuga||3803–3804|
|Japanese calendar||Taihō 3|
|Minguo calendar||1209 before ROC|
|Seleucid era||1014/1015 AG|
|Thai solar calendar||1245–1246|
829 or 448 or −324
— to —
830 or 449 or −323
Year 703 (DCCIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 703 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.
- Arab–Byzantine War: The Umayyad army under Abdallah ibn Abd al-Malik captures Mopsuestia in Cilicia from the Byzantines, and refortifies it, making it the first major Muslim stronghold in the area that will later become the Thughur.
- Musa ibn Nusayr, governor of Ifriqiya (western Libya), builds a Muslim fleet to harass the Byzantine navy and conquer the islands of Ibiza, Majorca, and Menorca (approximate date).
- Faroald II, duke of Spoleto, attacks the Exarchate of Ravenna in Italy, after the death of his father Thrasimund I. King Aripert II of the Lombards, desiring good relations with the Byzantine Empire and papacy, refuses to assist him.
- High King Loingsech mac Óengusso and his forces are routed during an invasion of Connacht (Ireland). He is killed by the men of King Cellach mac Rogallaig (approximate date).
- Wilfrid, Anglo-Saxon bishop, travels to Rome again, and is supported in his struggle to retain his see of York by the pope. On his way Wilfrid stops in Frisia (modern Netherlands), to visit Willibrord.
- Elias I becomes Catholicos of All Armenians.
- January 13 – Jitō, empress of Japan (b. 645)
- March 20 – Wulfram, archbishop of Sens
- Ergica, king of the Visigoths (or 701)
- Ermenilda of Ely, Anglo-Saxon abbess (approximate date)
- Loingsech mac Óengusso, high king of Ireland
- Thrasimund I, duke (dux) of Spoleto
- Treadgold, Warren T. (1997), A History of the Byzantine State and Society, Stanford, CA: Stanford University Press, pp. 337–339, ISBN 0-8047-2630-2
- Venning, Timothy, ed. (2006). A Chronology of the Byzantine Empire. Palgrave Macmillan. p. 189. ISBN 1-4039-1774-4.
- Levison England and the Continent pp. 50–51