|Centuries:||7th century – 8th century – 9th century|
|Decades:||760s 770s 780s – 790s – 800s 810s 820s|
|Years:||795 796 797 – 798 – 799 800 801|
|798 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1551|
|Bahá'í calendar||−1046 – −1045|
|English Regnal year||N/A|
|Chinese calendar||丁丑年 (Fire Ox)
3494 or 3434
— to —
戊寅年 (Earth Tiger)
3495 or 3435
|- Vikram Samvat||854–855|
|- Shaka Samvat||720–721|
|- Kali Yuga||3899–3900|
|Igbo calendar||−202 – −201|
|Japanese calendar||Enryaku 17
|Minguo calendar||1114 before ROC
|Thai solar calendar||1341|
|Wikimedia Commons has media related to 798.|
Year 798 (DCCXCVIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 798 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.
- Coenwulf of Mercia invades Kent, deposes and imprisons King Eadbert Praen, and makes his own brother Cuthred king.
- Sigered succeeds Sigeric as king of Essex.
- In the Battle of Bornhöved Slavic Obodrites led by Drożko defeated the Nordalbingian Saxons. In the coming years they were granted areas of nowadays Hamburg.
- Bahlul Ibn Marzuq revolted in Zaragoza against the central government of Muslim Al-Andalus.
- High water mark of Alfonso II of Asturias's campaigns against al-Andalus, the Christians sack Lisbon.
- Lu tung pin, Chinese historical figure and deity/immortal. Historical reference is at microcosmic orbit
- Abu Yusuf Ya'qub, jurist.
- Wonseong of Silla, 38th ruler of the Korean kingdom of Silla.
- Caradog ap Meirion (Caradog son of Meirion), was King of Gwynedd.
- Lu Mai, official of the Chinese dynasty Tang Dynasty.