Acording to Business Insider:
Land: 6.6 billion acres of land worldwide including
Great Britain, Northern Ireland, Canada, Australia and a few other spots
here and there. Also, the all-important Falkland Islands.
Background: England's third (and most likely soon to
be second) longest serving monarch, Elizabeth II retains royal title
over The British Commonwealth and as such manages to keep her face on
money throughout the globe.
With her 6.6 billion acres, Elizabeth II is far and away the world's
largest landowner, with the closest runner-up (King Abdullah) holding
control over a mere 547 million, or about 12% of the lands owned by Her
Majesty, The Queen.