The boards will be outlawed in 23 conservation areas from Olympia to Chelsea creating Britain's biggest “board free” zone.
The restrictions come into force over the next month after two councils got the go-ahead from the Government.
Hammersmith & Fulham councillor Nicholas Botterill said: “This is a victory for every resident who has had to put up with multiple, tatty, ugly and large signs that make roads look cluttered and shabby.”
Hammersmith & Fulham had bans in place in two conservation areas but will now add four more on October 5 after an application under the Town and Country Planning Act.
The new controls cover the Hammersmith Grove, the Olympia and Avonmore, the Gunter Estate and the Walham Green, Parsons Green and Moore Park conservation areas.
New restrictions in Kensington & Chelsea, which come into effect on September 27, mean that more than half the borough will be clear of “for sale” and “to let” signs.
It had bans in some conservation areas until they lapsed last year but the new controls cover a much bigger area and include the Norland, Colville, Pembridge, Chelsea Park/Carlyle, and Royal Hospital conservation areas.
Estate agents said the boards were no longer needed in London because most buyers looked for properties on websites.