WA residents from Broome, Port Headland, Karratha, Busselton and Perth all reported feeling shakes from the quake.
Some residents in Darwin in the Northern Territory also reported feeling tremors.
There is no threat of a tsunami to the Australian mainland, islands or territories.
'BREEZE STOPPED BLOWING'
Derby resident Jody Gaunt was having a beer with friends when they felt the quake.
"We were sitting outside and our chairs were rocking," she told AAP. "The trees stopped moving and the breeze stopped blowing.
"We were thinking, 'Is this real or not real?' We've never had an earthquake up here, or a tremor."
Ms Gaunt, 53, said the quake was the talk of the neighbourhood and it was reported that stock had been shaken off the shelves at the local Woolworths. The Roey Hotel employee Cindy told AAP she saw cars moving in the earthquake.
"I was outside and I just saw the cars moving. It was a bit scary. You could see them moving. A few things fell off the walls onto the floors," she said. "It just went for a few seconds." Gary, who works at the Mercure Hotel in Broome, said it started as a little shake before the doors and walls rattled.
"It started off with a shake, it was not too crazy and then it developed into quite a shake," he told AAP, after experiencing his first earthquake.
"It was quite nerve-racking. We made our way outside. It was not too strong, it almost felt like when you are in a car and the wind is a bit strong, and then it started picking up."
Locals took to social media to report they had felt the earth move. Deb Hannagan, from Broome, tweeted: "We just had an earthquake in Broome! The whole house was shaking and it went for ages. Never experienced anything like it before — quite amazing!"
The largest earthquake to hit WA was a magnitude 6.5. It hit the town of Meckering, not far from Perth, in October 14 1968 and reduced parts of the town to rubble.
That quake lasted for only 40 seconds but was felt 700km away.
More to come.
