| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century – 2nd century – 3rd century |
| Decades: | 100s 110s 120s – 130s – 140s 150s 160s |
| Years: | 135 136 137 – 138 – 139 140 141 |
| 138 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 138 CXXXVIII |
| Ab urbe condita | 891 |
| Armenian calendar | N/A |
| Assyrian calendar | 4888 |
| Bahá'í calendar | -1706–-1705 |
| Bengali calendar | -455 |
| Berber calendar | 1088 |
| English Regnal year | N/A |
| Buddhist calendar | 682 |
| Burmese calendar | -500 |
| Byzantine calendar | 5646–5647 |
| Chinese calendar | 丁丑年十二月初三日 (2774/2834-12-3) — to —
戊寅年十一月十二日(2775/2835-11-12) |
| Coptic calendar | -146–-145 |
| Ethiopian calendar | 130–131 |
| Hebrew calendar | 3898–3899 |
| Hindu calendars | |
| - Vikram Samvat | 194–195 |
| - Shaka Samvat | 60–61 |
| - Kali Yuga | 3239–3240 |
| Holocene calendar | 10138 |
| Iranian calendar | 484 BP – 483 BP |
| Islamic calendar | 499 BH – 498 BH |
| Japanese calendar | |
| Korean calendar | 2471 |
| Minguo calendar | 1774 before ROC 民前1774年 |
| Thai solar calendar | 681 |
Year 138 (CXXXVIII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Niger and Camerinus (or, less frequently, year 891 Ab urbe condita). The denomination 138 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.