| 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 |
| Bahá'í calendar | -1706 – -1705 |
| Bengali calendar | -455 |
| Berber calendar | 1088 |
| 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 | |
| - Bikram Samwat | 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 |
| Thai solar calendar | 681 |
Year 138 (CXXXVIII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar.