|Centuries:||1st century BC – 1st century – 2nd century|
|Decades:||50s 60s 70s – 80s – 90s 100s 110s|
|Years:||78 79 80 – 81 – 82 83 84|
|81 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||834|
|Chinese calendar||庚辰年 (Metal Dragon)
2777 or 2717
— to —
辛巳年 (Metal Snake)
2778 or 2718
|Coptic calendar||−203 – −202|
|- Vikram Samvat||137–138|
|- Shaka Samvat||3–4|
|- Kali Yuga||3182–3183|
|Iranian calendar||541 BP – 540 BP|
|Islamic calendar||558 BH – 557 BH|
|Minguo calendar||1831 before ROC
|Seleucid era||392/393 AG|
|Thai solar calendar||623–624|
Year 81 (LXXXI) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Silva and Pollio (or, less frequently, year 834 Ab urbe condita). The denomination 81 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.
- Domitian succeeds his brother Titus as emperor. Domitian is not a soldier like his two predecessors, and his administration is directed towards the reinforcement of a monarchy. By taking the title of Dominus ("lord"), he scandalizes the senatorial aristocracy. Romanisation progresses in the provinces, and life in the cities is greatly improved. Many provincials – Spanish, Gallic, and African – become Senators.
- The Arch of Titus is constructed.
- Pliny the Younger is flamen Divi Augusti (priest in the cult of the Emperor).
- The silver content of the Roman denarius rises to 92 percent under emperor Domitian, up from 81 percent in the reign of Vitellius.
- Archigene, Roman doctor (in Syria)
- Empress Deng Sui (d. 121)