New figures, published by KPMG, indicated 20% of employees earned less than the Living Wage - an increase of 1% from last year.
But Scotland had one of the lowest proportions of workers paid below the rate, 3% less than the UK average.
The Living Wage is set by an independent foundation and has been adopted by 380 Scottish firms.
The Living Wage Foundation sets its level based on a range of a cost of living measures such as accommodation, travel, healthy food and extras such as birthday presents.
It has just risen from £7.85 an hour to £8.25, making it nearly a fifth higher than the current national minimum wage and more than £1 higher than the the new minimum wage premium for over-25s of £7.20 an hour, due to come into force in April.
Glasgow University is the latest institution to become an accredited Living Wage employer
The research, conducted by Markit for KPMG, found East Renfrewshire had the highest percentage of workers earning below the Living Wage, at 32%, while the Western Isles had the lowest proportion at 11%.
The median hourly wage was £11.76 in Scotland compared to £11.61 for the UK as a whole.
Scotland's median wage per hour grew 1.5%, compared to 0.2% across the UK as a whole.
It has grown from below the UK average to 1.3% above the average since the same research was published a year ago.
The research also highlighted that part-time, female and young workers were most likely to earn below the Living Wage.
Part-time jobs were three times as likely to pay below £7.85 per hour as full-time roles.
For the third year, the research found that women were more likely to be paid below the Living Wage than men.
The data showed that an estimated 29% of females earned less than the rate, compared with 18% of males.
Nearly three quarters, 72%, of 18-21 year olds earned less than the Living Wage, compared to 17% of those aged 30-39.

Trevor Campbell, 59, from Sompting, was treated by paramedics but died at the scene.
He was struck at about 06:00 GMT on the eastbound carriageway in Lancing.
A 58-year-old man from Climping had been arrested on suspicion of causing death by careless driving.
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Mr Campbell, his wife Rosemary said the family was devastated.
She said he left a daughter, Ella, 28, and a granddaughter, Aerith, aged two.
"Trevor absolutely doted on Aerith, just as he did our own daughter, and his death is going to leave a huge gap in our family," she said.
Mr Campbell, a porter at Lancing College, was taking his usual walk to work when he was killed, police said.
Lancing College headmaster Dominic Oliver said he was a long-serving and loyal member of the team, and the Lancing community was saddened and shocked by his death.
A fifth of working people in Scotland are paid less than the voluntary Living Wage, according to research.
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A man arrested over the death of a pedestrian hit by a car on the A27 in West Sussex on Thursday has been released without charge.