Thanks to this world map that shows the density of people with the surname Giannioti in different countries, you can get an idea not only of the popularity of the surname Giannioti in each country but also of the different migrations of people surnamed Giannioti.
The quantity of people with the surname Giannioti that we can find in each country can help us discern the origin of the surname Giannioti, as logic tells us that the place with the most people surnamed Giannioti will be the country or area of origin of the surname Giannioti.