|Centuries:||5th century – 6th century – 7th century|
|Decades:||500s 510s 520s – 530s – 540s 550s 560s|
|Years:||535 536 537 – 538 – 539 540 541|
|538 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1291|
|Bahá'í calendar||−1306 – −1305|
|English Regnal year||N/A|
|Chinese calendar||丁巳年 (Fire Snake)
3234 or 3174
— to —
戊午年 (Earth Horse)
3235 or 3175
|- Vikram Samvat||594–595|
|- Shaka Samvat||460–461|
|- Kali Yuga||3639–3640|
|Igbo calendar||−462 – −461|
|Iranian calendar||84 BP – 83 BP|
|Islamic calendar||87 BH – 86 BH|
|Minguo calendar||1374 before ROC
|Thai solar calendar||1081|
|Wikimedia Commons has media related to 538.|
Year 538 (DXXXVIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Iohannes without colleague (or, less frequently, year 1291 Ab urbe condita). The denomination 538 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.
- March 12 – Siege of Rome: King Vitiges ends his siege (after 374 days) and abandons Rome. He retreats with his Gothic army northeast along the Via Flaminia.
- Belisarius attacks the Goths when they have crossed the Milvian Bridge. After fierce resistance, Vitiges routs in panic, and many are slain or drowned in the river.
- Gothic War: Vitiges strengthens the garrisons of various towns and besieges Ariminum. Byzantine forces under the Armenian general Narses arrive at Picenum.
- April – Belisarius secures Liguria, Mediolanum (modern Milan) and Ariminum, but disagreements, especially with Narses, leads to disunity in the Byzantine army.
- Summer – King Theudebert I sends a small Frankish force across the Alps, and defeats the Goths and Byzantines at the River Po. Belisarius retreats to Tuscany.
- Sittas, Byzantine general, suppresses a revolt in Armenia in protest against heavy taxation. During the campaign he is killed by Artabanes, leader of the revolt.
- King Cynlas Goch of Rhos abandons his wife in favour of his sister-in-law, a nun who he drags from her convent (approximate date).
- Gabrán mac Domangairt becomes king of Dál Riata (Scotland).
- The Third Council of Orléans takes place and prohibits rural labor on Sunday.
- Buddhism is introduced formally into Japan (by some accounts; see also 552).
- The prophetic time of the 1260 Years predicted in the Books Daniel and Revelation began.
- Bidatsu, emperor of Japan (d. 585)
- Gregory of Tours, bishop and historian (d. 594)
- Zhiyi, de facto founder of Tiantai Buddhism (d. 597)
- Cailtram, king of the Picts (approximate date)
- Comgall mac Domangairt, king of Dál Riata (approximate date)
- February 8 – Severus of Antioch, patriarch of Antioch
- Sittas, Byzantine general (magister militum)
- Damascius, Byzantine philosopher
- Procopius, De Bello Gothico II
- Procopius, De Bello Gothico I.XIII
- Martindale et al. p. 125, 255, 641