This works out as an average loss for each worker of over 5 thousand pounds.
372,786 people in Yorkshire & the Humber put in an average of 7.6 hours a week in unpaid overtime during 2017.
This averages at £5,641 a year that each of those workers is losing out in pay.
That's an average of £2.1 billion of free labour in 2017 by doing unpaid overtime, according to new analysis of official statistics published today by the TUC.
Across the UK public sector employees make up a quarter of total employees but produce more than a third of all unpaid overtime.
Today is the TUC's 14th annual 'Work Your Proper Hours Day'.
To mark the day, the TUC is asking workers to take a proper lunch break and leave on time. And managers should consider how to move away from over-reliance on unpaid overtime.
TUC Regional Secretary for Yorkshire & the Humber Bill Adams said:
"Lots of us are willing to put in a bit of extra time when it's needed. But it's a problem if it happens all the time. So today we're saying to workers in Yorkshire and the Humber, make sure you take a proper lunch break and go home on time.
"We're asking managers to leave on time too. Good bosses know that a long-hours culture doesn't get good results. And the best way to lead is by example".
"Public sector workers are more likely to work extra hours unpaid. It's a mark of how dedicated our public servants are - and it's kept our schools and hospitals in Yorkshire and the Humber running through years of funding cuts.
"But public service workers have also had eight years of real pay cuts, so they are being forced to do more for less. It's time the government gave them the fully-funded pay rise they have earned."