English: habitational name from any of the numerous places
throughout England called Kingston or Kingstone. Almost all of them,
regardless of the distinction in spelling, were originally named in
Old English as cyningestun ‘the king’s settlement’,
i.e. royal manor. However, Kingston upon Soar in Nottinghamshire is
named as ‘royal stone’, while Kingstone in Somerset is ‘king’s stone’;
both probably being named for some local monument.
Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4