Year 543 (DXLIII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. The denomination 543 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.
|Ab urbe condita||1296|
|Balinese saka calendar||464–465|
|Chinese calendar||壬戌年 (Water Dog)|
3239 or 3179
— to —
癸亥年 (Water Pig)
3240 or 3180
|- Vikram Samvat||599–600|
|- Shaka Samvat||464–465|
|- Kali Yuga||3643–3644|
|Iranian calendar||79 BP – 78 BP|
|Islamic calendar||81 BH – 80 BH|
|Minguo calendar||1369 before ROC|
|Seleucid era||854/855 AG|
|Thai solar calendar||1085–1086|
669 or 288 or −484
— to —
670 or 289 or −483
- Spring – Siege of Naples (542–543): The Byzantine garrison (1,000 men) in Naples surrenders to the Ostrogoths, pressed by famine and demoralized by the failure of two relief efforts. The defenders are well treated by King Totila, and the garrison is allowed safe departure, but the city walls are partly razed.
- The fortress city of Old Dongola (modern Sudan) along the River Nile becomes the capital of the Kingdom of Makuria. Several churches are built, including the "Old Church" (approximate date).
- Summer – Khosrow I, Shahanshah of the Sasanian Empire, invades Syria again, and turns south towards Edessa to besiege the fortress city.
- The Hephthalites threaten the Sasanian Empire from the East. They extend their domain in Central Asia (approximate date).
- A Byzantine invasion of Persarmenia is defeated at the Battle of Anglon by a much smaller force from the Sasanian Empire.
- King Pulakeshin I establishes the Chalukya dynasty in India. He extends his kingdom by conquering Vakataka and the west coast of Karnataka, giving him access to the valuable Arabian Sea trade routes.