RSM's survey of more than 1,500 UK consumers carried out by 3GEM found that 53 per cent of 25-34 year-olds said that they would consider a holiday offering a total break from their smartphones and tablets.
This was far higher than for any other age group, and higher than the average of 29 per cent across all age groups.
Travel operators are already responding to the growing demand, with many offering retreats with no wifi or mobile coverage. Some also offer spa treatments, forest bathing experiences, emotional therapies or activities such as yoga or cooking classes to cater for stressed-out millennials.
One enterprising hotel chain has also introduced 'social media sitters' who take over guests' accounts, posting updates and responding to comments. The service is designed to eliminate the stress of being inactive on social media.
Millennials also have the most diverse requirements when it comes to choosing a holiday, according to the research. Although beach holidays are the most popular break for millennials, they are less important than for other age groups, with a relatively higher number interested in foodie breaks, sporting holidays or wellness retreats.
Ian Bell, RSM's head of travel and tourism said: 'Our survey seems to contradict the notion that millennials are obsessed with choosing their holiday destination based on its instagrammability. Of course, this is true for some, but for many the idea of an off-grid experience away from the stresses of work emails, the 24-hour news cycle and social media one-upmanship is proving more of a draw. It might also reflect a growing awareness of the mental health benefits of switching off.
'Some travel operators are already responding to the trend, but we can see this sector of the market becoming increasingly important in 2019.'