Meet John. He's 59, and used to be a teacher.

He's also been job hunting for a decade, but has been rejected for even the most menial tasks.

"It's just a waste of time, they laugh at you," the single father said.

Key points: Almost 900,000 people in NSW live below the poverty line, research by the state's Council of Social Service found

Almost 900,000 people in NSW live below the poverty line, research by the state's Council of Social Service found More than one in six children live in poverty

More than one in six children live in poverty The poverty line is defined as earning 50 per cent less than the median household income

John, who wanted his surname withheld, is one of almost 900,000 people in NSW living below the poverty line, according to data released on Thursday by the NSW Council of Social Service (NCOSS).

Despite a strong state economy, more than one in six children across the state are living in poverty, and women are more likely to experience disadvantage than men.

Living below the poverty line is defined as earning 50 per cent less than the median Australian household income.

In Sydney, the most significant economic disadvantage is seen in the western suburbs of Guildford, Ashcroft, Miller, Fairfield and Lakemba.

In regional areas, Jesmond, Shortland, Port Kembla, Warrawong and Nambucca Heads are doing it the toughest.

John said he was lucky to have a roof over his head in Sydney but the expenses that come with such "a luxury" make life a constant battle.

"I manage on about $70 left over after all the bills … sometimes $20 per week," he said.

"And I always budget an extra $40 a week for my daughter … she comes first."

He often turns to homeless support services for food and said he had registered with four job agencies who had all told him the same thing — employers don't want men over 45.

"I want to do the right thing by my family, like many other middle-aged men, but it's hard," he said.

The NCOSS research found even securing work was not certain to alleviate financial pressure for people living below the poverty line.

According to their report, 107,000 full-time workers and over 76,000 part-time workers across NSW are living in poverty.

"Having a job doesn't make you immune," NCOSS chief executive Joanna Quilty said.

"And the notion that you can find cheaper housing on the edge of the city or if you move to the country, is not the case any longer."

Although there are more full-time workers in Sydney under the poverty line, those in the regions still experience far greater disadvantage due to isolation and increased costs.

This is particularly true for single-parent households — 65 per cent of which in far western NSW live in serious poverty.