In　this　study,　the　design　of　the　optimal　decentralised　full-state-feedback　controllers　is　derived　for　wireless　networked　control　systems　with　network-induced　delays.　In　particular,　the　authors　formulate　the　optimal　decentralised　control　problem　as　a　non-cooperative　linear　quadratic　game.　Then,　the　optimal　control　strategy　of　each　controller　is　obtained　that　is　based　on　the　current　plant　state　and　the　last　control　strategies　of　decentralised　controllers.　The　proposed　optimal　decentralised　controllers　reduce　to　the　known　controller　under　certain　conditions.　Moreover,　the　authors　illustrate　the　application　of　the　proposed　decentralised　state　feedback　control　to　load　frequency　control　in　power　grid　systems.