The research published by the York-based Joseph Rowntree Foundation found 22 per cent of the region’s residents are living below the poverty line.
In a sign of the squeeze from wage restraint and rising prices, more than half of those affected live in households were at least one person is in work.
The average weekly income in Yorkshire has risen by just £5 since the economic recovery began in 2010, the report suggests.
Helen Barnard, head of analysis at the Joseph Rowntree Foundation, said: “It is shocking that more than 1 in 5 Yorkshire and the Humber residents are living in poverty.
“The economy has been growing since 2010 but during this time high rents, low wages and cuts to working-age benefits mean that many families, including working households, have actually seen their risk of poverty grow.
“This report shows that people on low-incomes cannot rely on economic growth and rising employment alone to improve their financial prospects.
“Families who are just about managing urgently need action to drive up real-term wages, provide more genuinely affordable homes and fill the gap caused by cuts to Universal Credit, which will cost a working family of four almost £1,000 per year.”
With 51 per cent of those in poverty in Yorkshire in a household where someone works, this region has the highest rate of in-work poverty in the North.
The study by the New Policy Institute links rising levels of in-work poverty with the housing crisis.
Rising rents in the private sector are putting a major squeeze on standards of living with 27 per cent of those in poverty renting a home from a private landlord.
The report also closely links disability and poverty with a quarter of those affected disabled.
While the average weekly wage has actually fallen in recent years in the South-East, at 450 it remains well ahead of Yorkshire’s £375,
The JRF is calling for a range of measures including for the Government to completely reverse proposed cuts to the work allowance in the universal credit benefit.
Shadow Work and Pensions Secretary Debbie Abrahams said: “The Joseph Rowntree Foundation has shown the true impact of six wasted years of Tory austerity, with 7.4 million people in poverty in working households.
“This Government has no plan to tackle stagnant wages and rising insecurity, choosing instead to make the poorest pay for their economic mismanagement.”