|Centuries:||1st century – 2nd century – 3rd century|
|Decades:||70s 80s 90s – 100s – 110s 120s 130s|
|Years:||98 99 100 – 101 – 102 103 104|
|101 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||854|
|Chinese calendar||庚子年 (Metal Rat)
2797 or 2737
— to —
辛丑年 (Metal Ox)
2798 or 2738
|Coptic calendar||−183 – −182|
|- Vikram Samvat||157–158|
|- Shaka Samvat||23–24|
|- Kali Yuga||3202–3203|
|Iranian calendar||521 BP – 520 BP|
|Islamic calendar||537 BH – 536 BH|
|Minguo calendar||1811 before ROC
|Seleucid era||412/413 AG|
|Thai solar calendar||643–644|
Year 101 (CI) 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 Traianus and Paetus (or, less frequently, year 854 Ab urbe condita). The denomination 101 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.
- Emperor Trajan starts an expedition against Dacia, exceeding the limits of the Roman Empire set by Augustus.
- The Second Battle of Tapae is fought.
- Epictetus writes and publishes The Discourses.
Arts and sciences
- Plutarch writes his Parallel Lives of Famous Men (in Greek Βίοι Παράλληλοι) containing fifty biographies, of which 46 are presented as pairs comparing Greek and Roman celebrities—for example Theseus and Romulus, Alexander the Great and Julius Caesar, Demosthenes and Cicero.
- Gan Ying, an envoy of the Han dynasty in China who learned about Ta Ts'in (the Roman Empire), although he never reached there
- John the Apostle may have died this year in Ephesus (b. c. 6 AD)
- Saint Clement of Rome, Bishop of Rome (Epistle to the Corinthians) during the last decade of the first century
- Silius Italicus, author of Punicus (the annals of Hannibal during the Second Punic War) (b. c. 28 AD)