The Klang War or Selangor Civil War was a series of conflicts that lasted from 1867 to 1874 in the Malay state of Selangor in the Malay Peninsula (modern-day Malaysia). It was initially fought between , the administrator of the Klang Valley, and . It was joined by (Tengku Dhiauddin, also spelt Ziauddin), a Kedahan prince, as well as other Malay and Chinese rival factions. The war was eventually won by Tengku Kudin and Abdullah's son, Raja Ismail.