Teenagers score higher than young adults in their 20s on every level of subjective well-being, the study by the Resolution Foundation independent think-tank said.
As people move from their mid-50s towards retirement, all measures of subjective well-being rapidly increase, it found.
The "Happy now?" report analysed seven years of data from the Office for National Statistics, which first began to collect subjective well-being data under former prime minister David Cameron in 2011.
Many retirees reported higher happiness and self-worth than 20-year-olds. Well-being was also bolstered by employment, physical health, home ownership, having a partner - and being female.
Residents of Northern Ireland scored the highest levels of happiness, satisfaction and life-worth, while Londoners reported the lowest of every metric except happiness.
Owning a home correlates with higher happiness, with private renters reporting the lowest life satisfaction, the study said.