List of state leaders in 321

320 state leaders - Events of AD 321 - AD 322 state leaders - State leaders by year

Asia

• China (Sixteen Kingdoms Period)
  • Eastern Jin Dynasty - Emperor Yuan, Emperor of China (317–323)
  • Han Zhao - Liu Yao, Emperor of Han Zhao (318-329)
  • Later Zhao - Shi Le, Emperor of Later Zhao (319-333)
  • Cheng Han - Li Xiong, Emperor of Cheng Han (303-334)
  • Former Liang - Zhang Mao, Emperor of Former Liang (320-324)
• Gupta Empire - Chandragupta I, Gupta Ruler (319–335)
• Japan - (Ancient period) - Emperor Nintoku, emperor of Japan (c.313-c.399 traditional dates)
• Korea (Three Kingdoms Period)
  • Baekje - Biryu, King of Baekje (304–344)
  • Goguryeo - Micheon, King of Goguryeo (300–331)
  • Silla - Heulhae, King of Silla (310–356)
• Kushan Empire - Chhu, Emperor of the Kushans (c.310–325)
• Pallava - Simha Varman I, King of Pallava (315–345)

Europe

• Western Roman Empire
  • Constantine I, Roman Emperor (306–337)

Middle East

• Eastern Roman Empire
  • Licinius, Roman Emperor (308–324)