| Centuries: | 5th century BC - 4th century BC - 3rd century BC |
| Decades: | 340s BC 330s BC 320s BC - 310s BC - 300s BC 290s BC 280s BC |
| Years: | 321 BC 320 BC 319 BC - 318 BC - 317 BC 316 BC 315 BC |
| 318 BC by topic | |
| Politics | |
| State leaders - Sovereign states | |
| Birth and death categories | |
| Births - Deaths | |
| Establishments and disestablishments categories | |
| Establishments - Disestablishments | |
| Gregorian calendar | 318 BC |
| Ab urbe condita | 436 |
| Armenian calendar | N/A |
| Bahá'í calendar | -2161 – -2160 |
| Berber calendar | 633 |
| Buddhist calendar | 227 |
| Burmese calendar | -955 |
| Chinese calendar | 2319/2379 ([[Sexagenary cycle|]]年) — to —
2320/2380([[Sexagenary cycle|]]年) |
| Coptic calendar | -601 – -600 |
| Ethiopian calendar | -325 – -324 |
| Hebrew calendar | 3443 – 3444 |
| Hindu calendars | |
| - Vikram Samvat | -262 – -261 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 2784 – 2785 |
| Holocene calendar | 9683 |
| Iranian calendar | 939 BP – 938 BP |
| Islamic calendar | 968 BH – 967 BH |
| Japanese calendar | |
| Korean calendar | 2016 |
| Thai solar calendar | 226 |