The movement aims to show support for the fight against climate change.
"The world has shown it's ready to tackle the climate crisis," Senior Vice President for climate and energy at World Wildlife Fund, Lou Leonard said.
The Christchurch City Council says it doesn't have any plans for Earth Hour and it's up to individual residents to take part.
The Empire State Building, bright lights on the Las Vegas strip and other iconic landmarks will be flicking the switch in support.
Earth Hour starts this Saturday at 8:30pm.