List of state leaders in 290

289 state leaders - Events of AD 290 - AD 291 state leaders - State leaders by year

Africa

• Kush - Yesbokheamani, King of Kush (283–300)

Asia

• Armenia - Tiridates III, King of Armenia (283–330)
• China (Western Jin Dynasty) - Emperor Wu, Emperor of China (265–290)
• China (Western Jin Dynasty) - Emperor Hui, Emperor of China (290–307)
• Gupta Empire – Ghatotkacha, Gupta Emperor of India (280–319)
• Japan (Ancient period) - Emperor Ōjin, emperor of Japan (c.270-c.310)
• Korea (Three Kingdoms Period)
  • Baekje - Chaekgye, King of Baekje (286–298)
  • Goguryeo - Seocheon, King of Goguryeo (270–292)
  • Silla - Yurye, King of Silla (284–298)
• Kushan Empire – Vasudeva II, Emperor of the Kushans (c.290–310)

Europe

• Ireland - Fiacha Sraibhtine, High King of Ireland (285–322)
• Roman Empire
  • Gaius Aurelius Valerius Diocletianus, Eastern Augustus (284–305)
  • Marcus Aurelius Valerius Maximianus, Western Augustus (286–305)

Middle East

• Persia (Sassanid Dynasty) - Bahram II, Great King of Persia (276–293)