Top earners in Preston earn an average of £18,000 more per year than their lower-paid counterparts.
Campaigners have called for a change of culture in the business world, after figures from the ONS revealed "vast economic divides" across the UK.
In Preston, the average weekly pay packet for the top 20 per cent of earners among full-time workers in 2018 was two times higher than for the bottom 20 per cent.
The top earners were paid an average £681 per week - the equivalent of £35,420 per year.
For lower earners, average pay was just £335 per week, or £17,440 per year.
Luke Hildyard, director of independent think tank the High Pay Centre, said: "The UK is one of the most unequal developed countries in the world with some of both the richest and poorest regions in Western Europe.
"Most people are deeply uncomfortable with such wide divisions and rightly believe that we should be doing better.
"Corporate governance reforms, stronger trade union representation in low-paid, precarious industries and a change in business culture would all go a long way to building a fairer economy."
The average full-time employee in Preston works for 38.2 hours per week.
With a median salary of £23,899 per year, this means the average worker gets paid £12.03 per hour.
But the average hourly wage for the bottom 20 per cent of workers is just £8.78, compared to £17.83 for those at the top end of the scale.
The figures refer to just basic pay, and do not include bonuses or overtime.
Frances O'Grady, general secretary of the Trade Union Congress, called for the minimum wage to be increased to £10 an hour "as soon as possible".
She added that millions of people are stuck in low-paid jobs with little chance of progression, which is bad for both workers and national productivity.
“Many towns have been held back by lack of investment, leading to a shortage of solid jobs with good pay," she said.
"They need a fair chance to rebuild their local economy with government support through a new National Investment Bank."
The gap between the highest and lowest earners in Preston is smaller than the national average.
Across the UK, the average annual salary for the highest 20 per cent of earners is 2.3 times higher than for lower earners.
Top earners were paid £43,129 in 2018, compared to £18,970 for lower-paid workers - a gap of £24,160.
The region with the greatest gap was London, where the highest paid earned £54,798 in 2018, almost £32,200 higher than the lowest earners.
Most equal was Wales, where the highest 20 per cent of earners were paid £38,241, and the lowest £17,940.
Mr Hildyard continued: "These figures highlight the vast economic divides that exist in Britain, both within regions and local authorities, and between them.
"It's striking to see that the top earners in London earn 50 per cent more than even the highest paid workers in Wales and northern England.
"At the same time, the figures show how stereotypes of wealthy London and the South East mask the hardship experienced by many people in those regions, and the huge gaps between those at the top and at the bottom."