| Millennium: | 1st millennium BC |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 18 BC by topic |
| Politics |
|---|
| Categories |
| Gregorian calendar | 18 BC XVIII BC |
| Ab urbe condita | 736 |
| Ancient Greek era | 190th Olympiad, year 3 |
| Assyrian calendar | 4733 |
| Balinese saka calendar | N/A |
| Bengali calendar | −610 |
| Berber calendar | 933 |
| Buddhist calendar | 527 |
| Burmese calendar | −655 |
| Byzantine calendar | 5491–5492 |
| Chinese calendar | 壬寅年 (Water Tiger) 2680 or 2473 — to — 癸卯年 (Water Rabbit) 2681 or 2474 |
| Coptic calendar | −301 – −300 |
| Discordian calendar | 1149 |
| Ethiopian calendar | −25 – −24 |
| Hebrew calendar | 3743–3744 |
| Hindu calendars | |
| - Vikram Samvat | 39–40 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3083–3084 |
| Holocene calendar | 9983 |
| Iranian calendar | 639 BP – 638 BP |
| Islamic calendar | 659 BH – 658 BH |
| Javanese calendar | N/A |
| Julian calendar | 18 BC XVIII BC |
| Korean calendar | 2316 |
| Minguo calendar | 1929 before ROC 民前1929年 |
| Nanakshahi calendar | −1485 |
| Seleucid era | 294/295 AG |
| Thai solar calendar | 525–526 |
| Tibetan calendar | 阳水虎年 (male Water-Tiger) 109 or −272 or −1044 — to — 阴水兔年 (female Water-Rabbit) 110 or −271 or −1043 |
Year 18 BC was either a common year starting on Friday, Saturday or Sunday or a leap year starting on Saturday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a common year starting on Thursday of the Proleptic Julian calendar. At the time, it was known as the Year of the Consulship of Lentulus and Lentulus (or, less frequently, year 736 Ab urbe condita). The denomination 18 BC 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.