|Centuries:||7th century – 8th century – 9th century|
|Decades:||690s 700s 710s – 720s – 730s 740s 750s|
|Years:||717 718 719 – 720 – 721 722 723|
|720 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1473|
|Bahá'í calendar||-1124 – -1123|
|English Regnal year||N/A|
|Chinese calendar||己未年 (Earth Goat)
3416 or 3356
— to —
庚申年 (Metal Monkey)
3417 or 3357
|- Vikram Samvat||776–777|
|- Shaka Samvat||642–643|
|- Kali Yuga||3821–3822|
|Igbo calendar||-280 – -279|
|Japanese calendar||Yōrō 4
|Minguo calendar||1192 before ROC
|Thai solar calendar||1263|
|Wikimedia Commons has media related to 720.|
Year 720 (DCCXX) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 720 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.
- The Nihon Shoki (日本書紀), one of the oldest history books in Japan, is completed.
- Umayyad caliph Umar ibn Abd al-Aziz is succeeded by Yazid II ibn Abd al-Malik.
- July 30 – In the Tang Dynasty Chinese capital of Chang'an, the walls of a gated city ward collapse during the night, which unexpectedly form a large pool out in the open. This is most likely caused by a sinkhole created when ground water eroded the limestone bedrock beneath. As a consequence of this, more than 500 homes are destroyed (Benn, 50).
- The former governor of Iraq, Yazid ibn al-Muhallab, rebels and is defeated and killed by the Caliph's forces under Al-Abbas ibn al-Walid and Maslamah ibn Abd al-Malik.
- Bertrada of Laon, wife of Pippin III (d. 783)
- Pope Stephen III (d. 772)
- Baizhang, Chinese Zen Buddhist monk (d. 814)
- Sainte Odile, patron saint of Alsace
- Tariq ibn Ziyad, Moorish general
- Yeh Fa-shan
- Yazid ibn al-Muhallab, Arab governor of Iraq