The living wage is added to the minimum wage for workers aged 25 or over. It means the effective minimum wage will be £7.20 an hour from Friday, rising to nearly £9 an hour by 2020, up from the current minimum wage of £6.70.
Eligible workers will receive an 11% pay rise this year.
The Resolution Foundation says that people benefiting most from the introduction of the living wage are those living outside London and the South East, where wages are already relatively high.
Its research shows that 25% of employees in Northumberland, one in four, and 21% inCounty Durham, one in five, will receive a pay rise this year.
Torsten Bell, director of the Resolution Foundation, said: “The National Living Wage will transform the low pay landscape in the North East.
“Northumberland is the most affected area in the region, with one in four employees aged 25 and over set for a pay rise.
The proportion of employees to be affected by the introduction of the National Living Wage this year, by local authority:
Redcar and Cleveland: 26%
South Tyneside: 23%
County Durham: 21%
North Tyneside: 18%
Newcastle upon Tyne: 17%