The average property in the road, which lies just south of Kensington Gardens, costs just over £8m.
The borough of Kensington & Chelsea, long the home of embassies and ultra-rich foreigners, has 12 of the 20 most expensive streets in the country.
The figures have been compiled by Lloyds bank from Land Registry statistics between 2010 and 2015.
"Buyers want to be there [Kensington & Chelsea] from the status point of view, and are hedging their bets in the long term," said property commentator Henry Pryor.
But even for people for whom money is almost no object, buying homes for £8m is becoming much more costly.
The reforms to stamp duty, which came in last December, have dramatically increased the tax paid by buyers of the most expensive homes.
Anyone buying a house or flat worth more than £1.5m now pays 12% stamp duty on the value of the property above that level.
And the chancellor has announced that stamp duty will, next year, be increased even further for buyers of second homes.
"Someone buying a home for £8m would have paid £560,000 in stamp duty before last year's changes," said Mr Pryor.
"If they buy now they will pay £873,750, and after next year's stamp duty increase they will pay £1,113,750 if they are buying the property as second home."
Other expensive streets in Kensington & Chelsea include Egerton Crescent (£7.5m average price), Manresa Road (£7.3m) and De Vere Gardens (£6.6m).
Lloyds said that outside London, other clutches of ultra-expensive streets could be found in Surrey, such as Leys Road in Leatherhead and Icklingham Road in Cobham, where the average home costs £3.6m and £3m respectively.
Poole in Dorset is the only place outside London and the South East with streets among the top 50 most expensive roads in England and Wales.
Properties in Sandbanks Road cost on average just under £2.5m, closely followed by homes in Western Avenue and Haig Avenue.
In Wales, the most expensive street is Druidstone Road in Cardiff with an average price of £793,000.
Meanwhile a clutch of expensive streets can be found in Cheshire just south of Manchester.
The Land Registry statistics identify some streets in Wilmslow, Alderley Edge and Macclesfield as having average property prices of between £1.3m and £1.6m.
In a similar study, the Bank of Scotland, part of Lloyds Banking Group, said that Northumberland Street in Edinburgh was Scotland's most expensive street, with an average home there costing just over £1.3m.
Victoria Road in Kensington, west London, has again been named as the most expensive street in the UK.