Australians are becoming more connected online but also increasingly alone.

The most digitally connected - those aged 18 to 24 - are the most likely to be lonely, according to a landmark report into social connection across the nation.

One in three Australians report feeling lonely but stigma, shame and widespread misconceptions hinder attempts to seek help.

Michelle Lim, the report's author and chair of the national network of research organisations Ending Loneliness Together, said loneliness should be a public health priority but there had been little action.

"Loneliness should not be seen as a sign of weakness or fault," she said.

"Feeling lonely is an innate signal for us to acknowledge and address our basic human need for connection."

The experiences of more than 4000 Australians aged from 18 to 92 years old from across the country were documented in the report released on Monday to coincide with Australia's first-ever Loneliness Awareness Week.

Researchers defined loneliness as "a distressing feeling we get when we feel disconnected from other people and desire more (or more satisfying) social relationships".

Nearly one in four young adults reported always or often feeling lonely, compared with 15 per cent for the general population.

The findings contradicted the misconception that loneliness primarily affected older people.

The significant health impacts of loneliness were also laid bare.

Australians who feel lonely are twice as likely to have chronic disease and almost five times as likely to have depression.

"While the detrimental health, economic and social impacts of loneliness are well established, community awareness and action remain low," Dr Lim said.

Although most surveyed recognised loneliness is a serious issue, the majority said they wouldn't confide in others citing embarrassment and shame.

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