|Centuries:||7th century – 8th century – 9th century|
|Decades:||700s 710s 720s – 730s – 740s 750s 760s|
|Years:||735 736 737 – 738 – 739 740 741|
|738 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1491|
|Chinese calendar||丁丑年 (Fire Ox)
3434 or 3374
— to —
戊寅年 (Earth Tiger)
3435 or 3375
|- Vikram Samvat||794–795|
|- Shaka Samvat||660–661|
|- Kali Yuga||3839–3840|
|Japanese calendar||Tenpyō 10
|Minguo calendar||1174 before ROC
|Seleucid era||1049/1050 AG|
|Thai solar calendar||1280–1281|
|Wikimedia Commons has media related to 738.|
Year 738 (DCCXXXVIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. The denomination 738 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.
- Charles Martel, Merovingian mayor of the palace, begins a campaign against the Saxons (in modern-day Westphalia) on the northeast frontier. They are subdued and must pay him tribute.
- Kormesiy, ruler (khagan) of the Bulgarian Empire, is deposed by the nobility. He is replaced on the throne by his son Sevar who is a descendant of the royal Dulo clan.
- Felice Cornicola is appointed hypatos (Byzantine consul) and magister militum of Venice.
- King Swæfberht of Essex dies after a 23-year reign. He is succeeded by Saelred, a minor member of the Essex royal family.
- The Mayan city-state Xukpi (Copán) is defeated by a rival city-state, Quiriguá. Xukpi leader Uaxaclajuun Ub'aah K'awiil ("Eighteen Rabbit") is deposed thereafter.
- Boniface visits Rome, and is made papal legate of the Frankish Kingdom. He establishes many bishoprics in Bavaria.
- Áed mac Colggen, king of the Uí Cheinnselaig (Ireland)
- Asad ibn Abdallah al-Qasri, Arab governor
- Dluthach mac Fithcheallach, king of Uí Maine (Ireland)
- Fáelán mac Murchado, king of Leinster
- January 26 – John of Dailam, Syrian monk (b. 660)
- Maslama ibn Abd al-Malik, Arab general
- Suluk, Turkic ruler (khagan) of the Turgesh
- Swæfberht, king of Essex
- Uaxaclajuun Ub'aah K'awiil, Mayan ruler (ajaw)
- In the fiction of H. P. Lovecraft, Abd Al Azred, Muslim-kafir scholar and scientist, is killed in Damascus city market. His treatise on religion, the Al-Azif, is published soon thereafter.
- David Nicolle (2008). Poitiers AD 732, Charles Martel turns the Islamic tide (p. 19). ISBN 978-184603-230-1