The tremor struck about 3.30pm local time (0530 GMT) about 124 kilometres southeast of Townsville at a depth of 10 kilometres, according to the United States Geological Survey.
A low rumbling was felt at Magnetic Island, a 20-minute ferry ride from the mainland and part of the Great Barrier Reef, according to a hotelier at the All Seasons resort, where it briefly interrupted a wedding on the beach.
"Some of the guests felt a bit of a shake, nothing much. It wasn't major, no-one fell over and nothing was damaged," she said.
"It was just like a shudder, my office backs onto the laundry and I said 'Oh, that was a big spin cycle.' It hasn't stopped the world up here.
"We are alive and well at the moment and please God that's how we are going to stay."
There were no immediate reports of damage and no tsunami alert was issued.
In Townsville, a tropical city renowned for its easygoing lifestyle, residents said they hadn't felt a thing.
"Look, we're pretty laid-back around here and it'd take something more than that to shake us up," a publican at the local Molly Malone's Irish Bar told AFP.
Geoscience Australia seismologist David Jepsen said the epicentre was about 60 kilometres west of Bowen town, which was in the path of top-intensity Cyclone Yasi earlier this year.
"Fortunately this is a sparsely populated part of Queensland. We couldn't see much in the way of towns (in the quake zone), so that's a good thing," said Jepsen.
Australia rarely experiences significant earthquakes, its land mass being some distance from the boundary of the Indo-Australian tectonic plate.
Jepsen said that quakes of a magnitude 5.5 happened statistically once a year on average but Australia had experienced a "lull" in recent years.