Analysis of the Scottish labour market indicates that 470,000 people are now earning less than the living wage of £8.75 per hour.
It represents an increase of 53,000 on the 417,000 people cited in the report for 2012.
The hourly living wage rate for adults in 2012 was set at £7.20.
The study suggests that the health and education sectors have seen the largest increase in the number of people earning less than the living wage.
In health and social work services, 67 employees were earning less than the living wage in 2018 - an increase of 46% on the 46 people in 2012.
In education, 25 people were recorded as earning under the living wage - the number increased by 28% to 32 people in 2018.
In the accommodation and food services sector, 70 were earning less than the living wage in 2012. In 2018, this figure increased by 26% to 88.
Scottish Labour leader Richard Leonard said: “The rise in low pay across health and education in Scotland is alarming. The SNP should hang its head in shame.
“Those in the health and education sectors perform valuable work - they deserve much better than poverty pay.
“Under Labour work will pay, with a £10 per hour real living wage, a ban on zero-hours contracts and better rights with more security at work.
“Under the broken economy of the SNP and the Tories, more and more people are on poverty pay in Scotland this year, than last - including some of the most valued workers in society.
“Labour governments at Holyrood and Westminster have a plan to end poverty pay, including introducing a real living wage of £10 an hour and an industrial strategy that will deliver high-wage, high-skill jobs across Scotland.”
Business Minister Jamie Hepburn said: “Despite the UK Government’s austerity agenda, Scotland has the highest proportion of employees being paid at least the real Living Wage of all four UK nations. And we remain committed to driving forward inclusive growth in our economy.
“That is why we have committed in our Programme for Government to introduce fair work criteria to Scottish Enterprise job-related grants in 2019-20. This will focus on grant recipients paying the real Living Wage, not using exploitative zero hours contracts and meeting requirements to publish gender pay gap data.
“The First Minister has also set out out a ‘Fair Work First’ agenda to extend Fair Work criteria to as many funding streams, business support grants and public contracts as we can by the end of this Parliament.
“This means investment in skills and training; no exploitative zero hours contracts; action on gender pay; genuine workforce engagement, including with trade unions and payment of the real Living Wage.
“The STUC have welcomed this commitment and we will continue to work with them to maximise the impact of this agenda for workers across Scotland. With low pay one of the main drivers of in-work poverty, it’s vital that employers who can pay the real Living Wage do so”