A century old Adelaide pub has closed after being forced into voluntary liquidation by the weight of Australia's coronavirus restrictions.

The King's Head Hotel has been around since the 1870s and today became the first Adelaide pub to close permanently.

"It's been tough, there's been a lot of tears," publican Gareth Lewis told 9News.

An iconic Adelaide pub has closed down due to the coronavirus. (9News)

"I'm sure there's going to be more in the industry."

Mr Lewis has promoted local producers, suppliers and musicians at the William Street stalwart for 12 years.

But when pubs across the state were forced to close, his revenue dried up, and the bills kept coming.

"We got a gas bill yesterday – there's not four grand there to pay it, the revenue is zero," he said.

Mr Lewis attempted doing takeaway sales and running the old pub's bottle-shop, but the measures weren't enough to stop the bleeding.

Publican Gareth Lewis said there had been a lot of tears. (9News)

Industry figures say dozens more are at risk.

Mr Lewis has vowed to "sort out" any money owed, as he reflects on the venerable hotel's legacy.