|Centuries:||6th century – 7th century – 8th century|
|Decades:||640s 650s 660s – 670s – 680s 690s 700s|
|Years:||671 672 673 – 674 – 675 676 677|
|674 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1427|
|Bahá'í calendar||-1170 – -1169|
|English Regnal year||N/A|
|Chinese calendar||癸酉年 (Water Rooster)
3370 or 3310
— to —
甲戌年 (Wood Dog)
3371 or 3311
|- Vikram Samvat||730–731|
|- Shaka Samvat||596–597|
|- Kali Yuga||3775–3776|
|Igbo calendar||-326 – -325|
|Minguo calendar||1238 before ROC
|Thai solar calendar||1217|
|Wikimedia Commons has media related to 674.|
Year 674 (DCLXXIV) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. The denomination 674 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.
- Siege of Constantinople: The Arab fleet enter the Sea of Marmara and appear before the southern walls of Constantinople in an attempt to blockade the Byzantine capital.
- April – A Muslim expeditionary force disembark on the Thracian shore (near Hebdomon) and lay siege to the massive Theodosian Walls on the landward side to the west.
- Winter – Arab forces under Yazid (son of caliph Muawiyah I) retire to Cyzicus (Turkey). For the next 3 years the Arab fleet install a loose blockade around Constantinople.
- The Muslim-Arabs attack Crete, killing or enslaving much of the populace during the Muslim conquests (approximate date).
- King Ecgfrith of Northumbria defeats a coalition led by Mercians. He annexes the region of Lindsey (Lincolnshire).
- King Æscwine succeeds his father Cenfus as ruler of Wessex (approximate date).
- In Korea, Anapji is constructed by order of king Munmu of Silla.
- In Japan, princess Ōku proceeds to the Ise Jingu.
- Æthelthryth, former queen of Northumbria, gives large areas of land to bishop Wilfrid to found Hexham Abbey.
- Monkwearmouth monastery is founded by Benedict Biscop in Northumbria.
- The first glass windows are placed in English churches (approximate date).
- Abu Ayyub al-Ansari, friend (sahabah) of Muhammad (approximate date)
- Hassan ibn Thabit, Arab poet and companion of Muhammad
- Hongren, Chán (Buddhist) patriarch of the Tang Dynasty (b. 601)
- Seaxburh, queen of Wessex (approximate date)