There is one place named Mainland's Island in Canada.
All places in the world called "Mainland's Island".
Wellington (4)
Windsor (4)
Westport (3)
Milton (3)
Richmond (3)
Benton (3)
Saint Andrews (3)
Selkirk (3)
Tracadie (3)
Kingston (3)
Victoria (3)
Havelock (3)
Sidney (3)
Centreville (3)
Princeton (3)
Borden (3)
Cornwall (2)
Enterprise (2)
Hebron (2)
Lockeport (2)
Newcastle (2)
Roblin (2)
Sandy Lake (2)
Sydney (2)
Beaver (2)
Cambridge (2)
Charlottetown (2)
Delta (2)
Georgetown (2)
Kildonan (2)