The Resolution Foundation think tank said 40% of "millennials" - those born between 1980 and 1996 - were living in rented housing by the age of 30.
That was twice as many as "generation X" - those born between 1965 and 1980.
Up to a third of millennials face the prospect of renting from cradle to grave.
The report reveals that a record 1.8 million families with children rent privately, up from 600,000 15 years ago.
The accountancy firm PwC predicts that as the price of owning a home rises, 7.2 million households will be in rented accommodation by 2025, compared with 5.4m now and 2.3m in 2001.
Lindsay Judge, senior policy analyst at the Resolution Foundation, said: "Britain's housing problems have developed into a full-blown crisis and young people are bearing the brunt - paying a record share of their income on housing in return for living in smaller, rented accommodation.