The astonishing figure emerges just days before a state-of-the-nation analysis of poverty in Scotland is published. It has been revealed by the Child Poverty Action Group (CPAG) in Scotland, using research by the authoritative Institute for Fiscal Studies, which says between 50,000 and 100,000 more Scots children could be mired in poverty by the decade's end.
"It beggars belief that after so many years of progress in tackling poverty such a huge number of Scottish children could be made to suffer unnecessarily from a hugely disadvantageous start to life," John Dickie, head of CPAG in Scotland, told the Sunday Herald. "We genuinely fear that all the good work that has been done in reducing and preventing poverty will be undone, unless there is an urgent re-think of current UK Government tax and benefit policy."
One Labour MSP added that it was "appalling" that previous progress was being so dramatically reversed.
The detailed study, Poverty in Scotland 2014: the independence referendum and beyond, will be launched in Edinburgh on Thursday at an event to be addressed by Deputy First Minister Nicola Sturgeon and Jackie Baillie, shadow cabinet secretary for health, wellbeing and cities strategy.
The result of a unique collaboration between CPAG in Scotland, the Open University in Scotland, Glasgow Caledonian University and the Poverty Alliance, it draws together the expertise of academics, anti-poverty campaigners and other experts from across Europe.
The hope is that its release will focus extra political attention on poverty in the six months between now and the independence referendum on September 18.
The study says children are at greater risk of poverty than working-age adults and pensioners. Fully 20% of Scottish children, or 200,000, grew up in poverty in 2011-12, after housing costs are taken into account. Even by the yardstick of "before housing costs" used in international comparisons, 150,000 children, or 15%, live in poverty.
In Denmark and Norway, the respective figures are 10.2% and 9.4% .
Already, almost every council area in Scotland contains wards in which one-fifth of their children live in poverty.
Some progress was made by successive governments in reducing child poverty. Their numbers fell by 160,000 in Scotland alone between 1996-97 and 2011-12.
This trend came on the heels of dramatic increases in poverty between 1979 and the mid-1990s, and reflects the success of specific policy interventions.
A summary briefing of the study says: "A continued fall in poverty between 2009-10 and 2011-12, despite the economic downturn and wider austerity measures, has reflected the fact that as median incomes fell, the incomes of low-income households were protected, at least in part, because of previous investment in benefits and tax credits, and their uprating in line with inflation."
But this protection has been stripped away by cuts to benefits and the way in which they are uprated.
Tam Baillie, Scotland's commissioner for children and young people, said it was encouraging that there had been some reduction in the numbers of children living in poverty over the past five years, which showed that child poverty was not inevitable.
But, referring to the predicted increases, he said: "The cross-party commitment to end child poverty by 2020 is in tatters because - by these estimates - the numbers of children living in poverty will actually rise as a result of austerity measures suffered by the poorest people in society."
Pointing out that the impact of poverty on children is well documented - low birth weight, poor mental health, poor educational achievement and shortened life expectancy, Baillie added: "I am pleased that the referendum debate has rekindled a focus on the corrosive impact of child poverty.
"Children living in poverty are consigned to poorer life outcomes because of where they are born. We are a rich country, but we are an unequal society and as long as this remains the case, it is a blight on us all that we should be ashamed of."
Labour MSP Malcolm Chisholm, a member of Holyrood's cross-party group on children and young people, said: "Labour in government committed to abolishing child poverty by 2020 and this was on track when Labour was voted out of office.
"It is appalling that previous progress is being so dramatically reversed and I look forward to a Labour government next year giving priority once again to the abolition of child poverty."
Satwat Rehman, director of One Parent Families Scotland, said: "The reality for many single parents and their children is that social security is no longer a safety net in preventing extreme poverty.
"Welfare reform changes, with cuts to benefits and sanctions, are forcing low-income parents to choose between food for themselves and protecting their children. We must do better for our poorest children - they deserve better."