An Adelaide dog has broken the Guinness World Record for the loudest bark.

Six-year-old golden retriever Charlie registered his record-breaking bark of 113.1 decibels at a national competition late last year.

Judges have now confirmed that Charlie beat the previous record of 108 decibels, held by a German shepherd in London since 2009.

Charlie's owner, Belinda Freebairn, says her dog developed his bellowing bark - equivalent to the sound of a live rock band - at a young age.

"When he got a bit older, when he was about a year old, he just started to get that real deep bark and I knew he was really loud," she said.

"I think they roughly knew what the record was but I didn't really think he could beat it, I must admit... but he did.

"He doesn't bark at home at all really, he's really quiet."

It is the first time the record has been held by a dog in Australia.