|Centuries:||1st century – 2nd century – 3rd century|
|Decades:||140s 150s 160s – 170s – 180s 190s 200s|
|Years:||174 175 176 – 177 – 178 179 180|
|177 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||930|
|Chinese calendar||丙辰年 (Fire Dragon)
2873 or 2813
— to —
丁巳年 (Fire Snake)
2874 or 2814
|Coptic calendar||−107 – −106|
|- Vikram Samvat||233–234|
|- Shaka Samvat||99–100|
|- Kali Yuga||3278–3279|
|Iranian calendar||445 BP – 444 BP|
|Islamic calendar||459 BH – 458 BH|
|Minguo calendar||1735 before ROC
|Seleucid era||488/489 AG|
|Thai solar calendar||719–720|
Year 177 (CLXXVII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Commodus and Plautius (or, less frequently, year 930 Ab urbe condita). The denomination 177 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.
- Lucius Aurelius Commodus Caesar (age 15) and Marcus Peducaeus Plautius Quintillus become Roman Consuls.
- Commodus is given the title Augustus and is made co-emperor with the same status as his father Marcus Aurelius.
- Marcus Aurelius begins a systematic persecution of Christians at Rome, the followers take refuge in the catacombs.
- Churches in southern Gaul are destroyed after a crowd accuses the local Christians of practicing cannibalism and incest.
- Forty-seven Christians are martyred in Lyon (Saint Blandina and Pothinus, bishop of Lyon, are among them).
- Second Marcomannic War: Marcus Aurelius and Commodus begin war against the Quadi and the Marcomanni.
- Chinese troops suffer a crushing defeat against a confederacy of Central Asian tribes led by the Xianbei (see Wu Hu).
- Sun Yu (d. 215)
- Wang Can, Chinese politician, scholar and poet (d. 217)
- Xu Sheng, general of Wu (d. 228)
- Yuan Shang, youngest son of Chinese warlord Yuan Shao (d. 207)