Scottish Labour leader Kezia Dugdale described the gap as “shameful” and vowed her party had plans to close it.
Labour’s analysis of figures from the Office for National Statistics found in every age group, women earn less than men on average in Scotland, which builds up to a median of £60,000 less over a woman’s working life.
The SNP responded by claiming it had done more in government that any other party to promote gender equality in the workplace, adding that female employment in Scotland was among the highest in Europe.
Plans to close the gender pay gap in the Labour manifesto include introducing a £10 real living wage, forcing businesses to publish pay ratios and creating a civil enforcement system to ensure compliance with gender pay auditing.
Ms Dugdale said: “It is shameful that under the SNP and the Tories women in Scotland could earn £60,000 less than men on average well into their careers.
“Closing the gender pay gap isn’t just a question of fairness - it is essential for our economy.
“There is so much more to do to shatter the glass ceiling for women. Only Labour will take the radical steps to close the gap for good, like a real living wage and forcing companies to publish pay ratios.
“If a company thinks a woman is worth a lower wage than a man, then under Labour we’ll force them to admit it.
“This election is a choice between Scottish Labour MPs who will fight to close the gender pay gap, or SNP MPs who will fight for a second independence referendum that Scotland doesn’t need or want.”
SNP candidate for Aberdeen North, Kirsty Blackman, said: “The SNP Government has done more than any other to promote gender equality in the workplace and jobs market, with female employment being amongst the highest in Europe.
“On the other hand, Labour utterly failed over many decades to do enough on this when they had the chance.”
Previous research by PwC published in February found that the gender pay gap in Scotland currently stands at 15 per cent despite improved opportunities for women in the workplace.
The research found if this gap was closed, female earnings would increase by 18 per cent – an extra £5,300 per head per year.
The statistics were drawn from the professional services firm’s Women in Work research which measures levels of female economic empowerment across 33 countries.
It found the UK’s performance has improved due to increasing female employment rates, a narrowing of the gender pay gap and a reduction of the gap between male and female labour force participation rates.
The UK now ranks 13th out of 33 Organisation for Economic Co-operation and Development (OECD) countries, and is second only to Canada in the G7 group of nations.
In total, this figure would be £6.5 billion for Scotland.
UK regional variations in the gender pay gap were calculated using the difference between the median gross weekly pay for men and women as a percentage of the median gross weekly pay for men.
Northern Ireland was found to have the lowest pay gap at 6 per cent, while the West Midlands has highest gap at 27 per cent.
The UK average is 17 per cent.
MSPs launched a probe on the issue earlier in the year after a Holyrood report found that it could be 2069 before the gender pay gap closes.
The largest pay gaps are found in senior management levels and the skills trade.
The probe by Holyrood’s Fair Work committee is looking at whether the issue is holding back Scotland’s economy amid UK-wide findings that equalising women’s productivity could add almost £600 billion to the economy. If the 2.2 million women who wanted to work could find suitable jobs, 10% could be added to the size of the economy by 2030.
Committee convenor Gordon Lindhurst MSP said in February: “Equal pay is still not a reality for many working people in Scotland. An important question for the committee will be: is this holding back Scotland’s economic growth?
“The committee will examine whether addressing the gender pay gap could positively affect Scotland’s business performance.”