|242 by topic|
|Ab urbe condita||995|
|Balinese saka calendar||163–164|
|Chinese calendar||辛酉年 (Metal Rooster)|
2938 or 2878
— to —
壬戌年 (Water Dog)
2939 or 2879
|Coptic calendar||−42 – −41|
|- Vikram Samvat||298–299|
|- Shaka Samvat||163–164|
|- Kali Yuga||3342–3343|
|Iranian calendar||380 BP – 379 BP|
|Islamic calendar||392 BH – 391 BH|
|Minguo calendar||1670 before ROC|
|Seleucid era||553/554 AG|
|Thai solar calendar||784–785|
368 or −13 or −785
— to —
369 or −12 or −784
Year 242 (CCXLII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Gratus and Lepidus (or, less frequently, year 995 Ab urbe condita). The denomination 242 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.
- Emperor Gordian III begins a campaign against King Shapur I; Greek philosopher Plotinus joins him, hoping to obtain first-hand knowledge of Persian and Indian philosophies.
- Gordian III evacuates the Cimmerian cities in the Bosphorus (Crimea), as the territory is now controlled by the Goths.
- Shapur I makes a pre-emptive attack on Antioch to drive out the Romans. Gordian's father-in-law, Timesitheus, leads a Roman army to defeat the Sassanids at Carrhae and Nisibis.
- King Ardashir I, founder of the Sassanid Empire, dies after a 30-year reign. He is succeeded by his son and co-ruler Shapur I.
- Patriarch Titus succeeds Eugenius I as Patriarch of Constantinople (until 272).
- Ammonius Saccas, Egyptian philosopher (b. 175)
- Ardashir I, king of the Sassanid Empire (b. 180)
- Cao Hui, Chinese prince of the Cao Wei state
- Man Chong (or Boning), Chinese politician