Australia's 500 biggest companies revealed

O-I's five glass factories in Australia and New Zealand recorded $750 million in revenue in 2018 and $140 million in earnings, making beer bottles for the likes of Lion, Asahi and Heineken.

Visy will by 2021 have also enjoyed a full year of the post-pandemic boom in online shopping, which has made its box-making division one of the few places to be hiring aggressively at the moment.

"Online retail in Australia went from $4 billion in March to $8 billion in May, and that's all coming to you in a corrugated box," Visy chairman Anthony Pratt told the Financial Review in July.

Visy was not the only private company in the Top 500 to benefit from ecommerce's big moment.

New Aim, which sells China-sourced merchandise via portals like eBay and Catch Of The Day, grew revenue 59 per cent to $285 million, to place 235th on the list.

Certain sectors reliant on bricks-and-mortar retailing did well too, notably Australia's largest manufacturer of toilet paper, ABC Tissue.

Booktopia was a big winner, growing sales 24 per cent to $163 million in part because of the acquisition of the University Co-op's online bookstore, but also because a big competitor was looking elsewhere as COVID-19 hit.

"With bookstores closed and Amazon focused on essentials, it meant that Booktopia was one of the few retailers serving the Australian public for their book purchases," said founder Tony Nash.

Meanwhile One Stop Warehouse, which sells solar panels and renewables-focused electricity plans online, grew revenue 31 per cent to $512 million.

Founder Anson Zhang attributed the result to careful monitoring of cashflows and inventories, so that One Stop never ran out of stock even when its factory suppliers or ports were shut.

Certain sectors reliant on bricks-and-mortar retailing did well too, notably Australia's largest manufacturer of toilet paper, ABC Tissue.

Its revenue rose 16 per cent to $617 million in 2019-20, caused almost entirely by the pandemic-induced panic buying of toilet rolls that occurred in the early lockdown days of March and April.

Meanwhile, electronics retailer Bing Lee grew 23 per cent to $431 million as people tooled up to work from home.

They're eating more at home too, which has primed the top line at Perfection Fresh Group by 16 per cent to $620 million. It credited the growth to product lines such as its Calypso mangoes, Qukes baby cucumbers, and Broccolini, a name it has trademarked after introducing the crunchy green vegetable to Australian in 1999.

It's nothing but red at privately owned airports, however. With freight about the only thing easily allowed to fly, Brisbane Airport's income fell 15 per cent to $713 million, Adelaide Airport's nosedived 16 per cent to $165 million, while Queensland Airports dropped 17 per cent to $120 million.

The only airports to report growth on the Top 500 Private Companies list were Melbourne and Perth, but only because their 2019-20 financials were not available when it was compiled.

A host of other hospitality and in-person service businesses suffered too.

Revenue at Anytime Fitness shrank 18 per cent to $330 million thanks to mandated closures, even as its franchise network of gyms grew from 506 to 513 over the year.

Pub group Federal Hotels fell 16 per cent to $444 million revenue, and reported that it would have been worse if not for its bottle shops and its transport subsidiary, aptly named COPE.

Just Cuts fell a whopping 47 per cent to $118 million, as its salons were forced to close for all of April, and people began investing in clippers to try haircuts at home.

Big4 Holiday Parks was another big COVID-19 loser, down 22 per cent to $315 million as all its sites were off-limits from April to June.

IBISWorld compiles the Top 500 Private Companies list by gathering primary research, ASIC-lodged company reports and its own appraisals of company revenue based on historic data and industry analysis.