Surname Grantson (Grantson 
) , in the entire world, is a rare cognomen. The cognomen Grantson is habitual in Ghana, where it is a rare surname, Canada, where it is an extremely rare surname, and the United Kingdom. Measured by absolute frequency, it most frequently occurs in Ghana, the United States, and the United Kingdom. Much less frequently, Grantson is the forename as well as the last name.