The research, funded by the Nuffield Foundation, is the UK's largest study into how adults are feeling during lockdown. More than 70,000 people have been questioned weekly over the past 14 weeks.
Almost half (46 per cent) of the participants said they had not been enjoying the restrictions while 21 per cent reported mixed feelings.
Just 4 per cent said they had enjoyed the period "very much", compared with 17 per cent of people saying they had not enjoyed it "at all".
Overall, people in Scotland and Wales have liked spending time in lockdown less than those in England.
Lead author Dr Daisy Fancourt, from UCL's Institute of Epidemiology & Health Care, said: "Our study shows that the majority of people are either not enjoying the lockdown or have mixed feelings about it.
"This is especially true amongst groups with a lower household income, who may be living in accommodation which is overcrowded or lacking in outside space, and those living alone, who may be feeling more isolated than those living with others.
"Of the third of people who report enjoying lockdown, a large number have higher household incomes and live with others or children, suggesting these people may have been less affected by the economic and social restrictions."
Asked if they would miss lockdown, 36 per cent said they would not miss it at all, but more than a quarter (26 per cent) said they would miss it more than not miss it.
The study also looked at behavioural changes, and found that four in 10 UK adults said they have gained weight.
A third of smokers said they were smoking more than usual, while 17 per cent of drinkers said they were consuming more alcohol.
Cheryl Lloyd, education programme head at the Nuffield Foundation, said: "Given that low earners have been most at risk of the negative social and economic consequences of the pandemic it is unsurprising that they have been less likely to enjoy lockdown than those on higher incomes.
"It is essential the policy response takes steps to reduce inequalities and minimise the longer-term scarring effects of the pandemic on low earners."