Some 30 British companies are expected to take part in the pilot, which will see no loss in pay for employees working one fewer day a week.
Instead they will be asked to maintain 100% productivity for 80% of their time.
The pilot has been launched by 4 Day Week Global in partnership with think tank Autonomy, the 4 Day Week UK Campaign and researchers at Cambridge University, Oxford University and Boston College.
Joe O’Connor, pilot programme manager for 4 Day Week Global, said: ‘More and more businesses are moving to productivity focused strategies to enable them to reduce worker hours without reducing pay.
‘We are excited by the growing momentum and interest in our pilot program and in the four-day week more broadly.
‘The four-day week challenges the current model of work and helps companies move away from simply measuring how long people are “at work”, to a sharper focus on the output being produced. 2022 will be the year that heralds in this bold new future of work.’
The UK pilot will run alongside other trials across the US, Ireland, Canada, Australia and New Zealand.
Governments in Spain, and also Scotland, have already launched trials of the four-day week after Nicola Sturgeon promised ‘a better work-life balance’ in her election manifesto.
The companies involved in the pilot, including tech firm Canon, will be offered a package of support including workshops, mentoring, networking and access to world-class academic research.
Researchers will work with each organisation to measure the impact on productivity, the wellbeing of workers, and the impact on the environment and gender equality.
Several studies have shown that moving to a four-day week boosts productivity and the wellbeing of staff.
When Microsoft trialled a four-day week with no loss of pay in their Japan office, productivity went up by 40%.
Six UK companies have signed up to the trial so far, with other firms said to be considering it including Unilever, which produces consumer goods like Dove soap and Vaseline, and Morrisons for its employees in its headquarters.
App-based Atom Bank permanently moved all of its 430 staff to a four-day, 34-hour working week with no reduction in pay in November.
Brendan Burchell, professor in social sciences at Cambridge University, said: ‘With the social and environmental benefits of the shorter working week becoming clearer, grassroots support more widespread, and technology available to maintain productivity, the time has come for more organisations to take the leap and unravel the practicalities.
‘This scheme has tremendous potential to progress from conversations about the general advantages of a shorter working week to focussed discussions on how organisations can implement it in the best possible way.’