In Hammersmith and Fulham, the wait is 23 years; in Westminster, 27 years; in Brent, 18 years; in Ealing and Harrow, first-time buyers have a 16 year wait; in Hounslow, the average is 14 years; and in Hillingdon, it's 12 years.
The average wait in England is around 13 years.
The House of Commons Library analysis, commissioned by MP Tessa Jowell and released on Tuesday (February 24), shows the true impact of London's housing crisis on people trying to get a foot on the ladder.
Figures are based on looking at average earnings alongside average house prices in an area, from 2013, and how long it would take for an individual working full-time to save a typical 10% deposit.
In Kensington and Chelsea, average earnings were £43,000 while the average house price was a staggering £975,000.
In Hammersmith and Fulham, average earnings were recorded as £35,000 and the mean house price was £563,500, while in Westminster average earnings were found to be £38,000 with the average house price at £725,000.
Ms Jowell, MP for Dulwich & West Norwood, said: “We need to build one London, not two, where everyone has the chance to live in a decent home and first time buyers aren’t excluded from the housing market unless they have access to the bank of mum and dad.
“The next Mayor has to build many more homes, plain and simple, but we also have to develop a serious plan to help thousands more Londoners get on the housing ladder.
“A more equal London has to mean it’s possible to buy your own home."