Russians, Brazilians and Malaysians are the most likely to visit places linked to the Royal Family.
The Tower of London – where Anne Boleyn was beheaded – is the most popular royal attraction, with 2.38 million foreign visitors last year.
St Paul’s Cathedral which held the wedding of the Prince of Wales and Diana, Princess of Wales, saw 1.8 million overseas visitors in 2009.
Buckingham Palace attracted 402,000 visitors even though it is only open for eight weeks a year, while Windsor Castle saw 987,000 foreign visitors.
The survey, by VisitBritain, analysed information from 50,000 people who took part in the 2009 International Passenger Survey.
Of the 30 million overseas visitors who came to Britain last year 5.8 million visited a castle, 5 million a historic house and 6.4 million a religious monument such as a cathedral.
In a separate questionnaire, 25,000 people were asked to rank a series of 15 iconic pictures of Britain and the Queen came third.
Last year, tourists from other countries spent £4.6 billion on “culture and heritage” – including theatres, galleries, pubs and premier football.
Sandie Dawe, from VisitBritain, said: “This research shows Britain’s monarchic heritage draws foreign tourists to just about every corner of the country from Scotland to Cornwall.
“Her Majesty the Queen celebrates her Diamond Jubilee in 2012, a feat last accomplished back in 1897 by Queen Victoria.
“This report suggests that year she is going to generate a bonanza for British tourism.”
Top 10 British icons
1) Double decker red bus
2) Scottish castle
3) The Queen
4) Red telephone boxes
5) Stone houses
6) Union Jack
7) The London Eye
8) Football match
9) Draught beer
10) Green countryside