The earliest reference I have found to this house is in March 1814 in the will of Paul Webb, tobacco pipe maker of 79 Great Peter Street. One of the witnesses is “James Whitby, Queen Head, Marsham Street”, but it is not stated if Mr Whitby was the Licensee. It stood on the corner of Marsham Street and Great Peter Street, and appears as 48 Great Peter Street in the 1851 Census. It survived until at least 1952. * 
The address is at 68 Marsham street for much of its life, certainly from at least 1833; and alters sometime between 1921 and 1927 to 68 Marsham street. This is a pure renumber of the houses on the West side of Marsham street, and the building never moves during any of this time. At 45 Great Peter Street in the 1861 census.
Westminster St John index
Historical London public houses, Taverns, Inns, Beer Houses and Hotels.

Queens Head, Marsham Street SW1 - Licensee Harry Robson
Kindly provided by Peter Fry
Residents at this address.
1811/James Whitby, Queens Head, Great Peter street, Westminster/../../Holdens Directory
1825/Mr Whitby/../../../Licensed Victuallers Association 
1833-34/James Whitby, Queens Head, 68 Marsham street, Westminster/../../Pigot's Directory 
1839/William Smith, Queens Head, 68 Marsham street, Westminster/../../ Pigot’s Directory *
1841/F Young/../../../ Trade Directory *
1843/Fred Young/../../../Kellys Directory 
1848/John M Young/../../../Post Office Directory 
8th Aug 1850/License transfer from the executors of John Mates Young (decd.) to Francis William Sanderson/../../../ The Era *
1851/William Sanderson/../../../Kellys Directory 
1851/Francis W Sanderson/Victualler/30/Tottenham, Middlesex/Census *
1851/Margaret Sanderson/Wife/35/Soho, Middlesex/Census
1851Francis W Sanderson/Son/1/Newington, Surrey/Census
1851/Ann Knight/General Servant/16/Brighton, Sussex/Census
25th May 1852/License transfer from Francis William Sanderson to George Eason/../../../ The Era  *
1856/G Eason/../../../Post Office Directory 
1861/George Eason/Licensed Victualler/40/Teynham, Kent/Census
1861/Marianne Eason/Wife/35/Westminster St John, Middlesex/Census
1861/Louisa Eason/Daughter/7/Westminster St John, Middlesex/Census
1861/Isabella Eason/Daughter/4/Westminster St John, Middlesex/Census
1861/Helena Eason/Daughter/4/Westminster St John, Middlesex/Census
1861/Marianne Hedgenlow/Visitor, Widow/65/Westminster St John, Middlesex/Census
1861/Ann Finch/Servant/24/Sudbury, Suffolk/Census
1861/Charles Youens/Visitor/17/Westminster St Margarets, Middlesex/Census
1861/Hy Leeson/Servant/26/Buckinghamshire,/Census
1861/Josh Leeson/Servant/23/Buckinghamshire,/Census
1861/George Griffiths/Servant/20/Stonehouse, Devon/Census
1861/Frederick Pond/Servant/22/Wandsworth, Surrey/Census
1865/Mr George Eason/../../../Licensed Victuallers Institution 
1866/George Eason/../../../Post Office Directory 
1869/G Eason/../../../Post Office Directory 
1877/Benjamin Young/../../../Post Office Directory 
1881/Benjamin Young/Licensed Victualler/26/Westminster, Middlesex/Census 
1881/F Jane Young/Wife/27/Westminster, Middlesex/Census
1881/Edith Young/Daughter/14 months/Westminster, Middlesex/Census
1881/Anne E Reade/Visitor/22/Leigh, Essex/Census
1881/Patrick Fitzgerald/Barman/26/London, Middlesex/Census
1881/Samuel Welstead/Potman/20/London, Middlesex/Census
1882/Benjamin Young/../../../Post Office Directory 
1884/Benjamin Young/../../../Post Office Directory 
1891/William Young/../../../Post Office Directory 
1893/Mrs Alice Young/../../../Post Office Directory 
1895/James William Ellis/../../../Post Office Directory 
1899/Richard Smith, Queens Head, 68 Marsham street, Westminster/../../Post Office Directory 
1903/John Sayers/Queens Head, 68 Marsham Street/../../Hughes Directory 
1910/John Sayers/Queens Head, 68 Marsham Street/../../Hughes Directory 
1921/John Sayers/Queens Head, 68 Marsham Street/../../Hughes Directory 
1927/B W Twidle/Queens Head, 2 Marsham Street/../../Hughes Directory 
1930/Edgar Freeman Lyne/Queens Head, 2 Marsham Street SW1/../../Post Office Directory 
1934/Edward Albert Lester/Queens Head, 2 Marsham Street SW1/../../Post Office Directory 
1938/Harry Robson/Queens Head, 2 Marsham Street SW1/../../Post Office Directory 
1944/Harry Robson/Queens Head, 2 Marsham Street/../../Post Office Directory 
 * Provided By John Hills