List of state leaders in 18
AD 17 state leaders – Events of AD 18 – AD 19 state leaders – State leaders by year
Africa
Asia
Europe
- Atrebates – Verica, King of the Atrebates (15–40)
- Bosporan Kingdom – Tiberius Julius Aspurgus, Roman client King of Bosporus (8 BC–38 AD)
- Catuvellauni – Cunobelinus, King of the Britons and King of the Catuvellauni (9–40)
- Caucasian Iberia – Aderk, King of Caucasian Iberia (1–30)
- Ireland – Feradach Finnfechtnach, High King of Ireland (14–36)
- Marcomanni – Marbod, King of the Marcomanni (9 BC–19 AD)
- Odrysian kingdom
- Roman Empire (Principate – Julio-Claudian dynasty)
- Tiberius, Roman Emperor (14–37)
- Tiberius, Consul (18)
- Germanicus, Consul (18)
- Lucius Seius Tubero, Consul suffectus (18)
- Livineius Regulus, Consul suffectus (18)
- Gaius Rubellius Blandus, Consul suffectus (18)
- Marcus Vipstanus Gallus, Consul suffectus (18)
- Sejanus, Praetorian prefect (14–31)
- Africa Province – Marcus Furius Camillus, Roman governor (17–19)
- Ægyptus Province – Gaius Valerius, Roman Prefect (16–31)
- Judea (Iudaea Province)
- Syria Province – Gnaeus Calpurnius Piso, Roman Prefect (17–19)
Middle East