|Centuries:||6th century – 7th century – 8th century|
|Decades:||660s 670s 680s – 690s – 700s 710s 720s|
|Years:||688 689 690 – 691 – 692 693 694|
|691 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1444|
|Bahá'í calendar||−1153 – −1152|
|English Regnal year||N/A|
|Chinese calendar||庚寅年 (Metal Tiger)
3387 or 3327
— to —
辛卯年 (Metal Rabbit)
3388 or 3328
|- Vikram Samvat||747–748|
|- Shaka Samvat||613–614|
|- Kali Yuga||3792–3793|
|Igbo calendar||−309 – −308|
|Minguo calendar||1221 before ROC
|Thai solar calendar||1234|
|Wikimedia Commons has media related to 691.|
Year 691 (DCXCI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. The denomination 691 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.
- King Theuderic III dies and is succeeded by his son Clovis IV, age 9, as sole ruler of the Franks. He becomes a puppet—a roi fainéant—of his uncle Pepin of Herstal, mayor of the palace of Austrasia.
- Battle of Maskin: A Umayyad army under caliph Abd al-Malik ibn Marwan defeat the rebel forces in Mesopotamia (modern Iraq). He reconquers the Arabian Peninsula, taking the holy city of Medina.
- The Dome of the Rock is completed in Jerusalem during the Second Fitna, becoming the first work of Islamic architecture.
- Wilfrid, abbot of Ripon, tries to make himself bishop of all Northumbria. King Aldfrith seizes many of his Ripon Abbey estates and proposes to create a bishopric there. Wifrid is banished and flees to Mercia where king Æthelred makes him bishop of Leicester.
- November 7 – Cen Changqian, official of the Tang Dynasty
- Fithceallach mac Flainn, king of Uí Maine (Ireland)
- August 24 – Fu Youyi, official of the Tang Dynasty
- November 7 – Ge Fuyuan, official of the Tang Dynasty
- Sun Guoting, Chinese calligrapher (b. 646)
- Theuderic III, king of the Franks (b. 654)
- Slavik, Diane (2001). Cities through Time: Daily Life in Ancient and Modern Jerusalem. Geneva, Illinois: Runestone Press, p. 60. ISBN 978-0-8225-3218-7