|Millennium:||1st millennium BC|
|294 BC by topic|
|Gregorian calendar||294 BC|
|Ab urbe condita||460|
|Ancient Egypt era||XXXIII dynasty, 30|
|- Pharaoh||Ptolemy I Soter, 30|
|Ancient Greek era||121st Olympiad, year 3|
|Balinese saka calendar||N/A|
|Chinese calendar||丙寅年 (Fire Tiger)|
2403 or 2343
— to —
丁卯年 (Fire Rabbit)
2404 or 2344
|Coptic calendar||−577 – −576|
|Ethiopian calendar||−301 – −300|
|- Vikram Samvat||−237 – −236|
|- Shaka Samvat||N/A|
|- Kali Yuga||2807–2808|
|Iranian calendar||915 BP – 914 BP|
|Islamic calendar||943 BH – 942 BH|
|Minguo calendar||2205 before ROC|
|Seleucid era||18/19 AG|
|Thai solar calendar||249–250|
−167 or −548 or −1320
— to —
−166 or −547 or −1319
Year 294 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Megellus and Regulus (or, less frequently, year 460 Ab urbe condita). The denomination 294 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.
- Archidamus IV, king of Sparta, son of Eudamidas I and grandson of Archidamus III, is defeated by Demetrius Poliorcetes of Macedonia in a battle at Mantinea. Sparta is saved only because Demetrius is called away by the threatening activities of his rivals Lysimachus and Ptolemy.
- Alexander V of Macedon is ousted by his brother, Antipater II. Therefore Alexander V turns to Demetrius Poliorcetes for help in recovering his throne. However, Demetrius Poliorcetes establishes himself on the throne of Macedonia and then murders Alexander V. Antipater II loses the throne of Macedonia but is able to survive.
- Pyrrhus of Epirus exploits the dynastic quarrel in Macedonia involving Alexander V of Macedon, his brother, Antipater II and Demetrius Poliorcetes to take over the frontier areas of Parauaea and Tymphaea, along with Acarnania, Ampholochia, and Ambracia.
- Lysimachus concludes a peace with Demetrius Poliorcetes whereby Demetrius Poliorcetes is recognized as ruler of Macedonia.
- Stratonice, daughter of Demetrius Poliorcetes and wife of Seleucus marries her stepson Antiochus. Seleucus has reportedly instigated the marriage after discovering that his son by his late wife Apama was in danger of dying of lovesickness as he has fallen in love with his beautiful stepmother.