Should I use a comma between a city and a country/a city and a state?

In geographical names with two or more elements, you should use a comma after each different element. This helps the reader to see the different component parts of the address. You should also use a comma after the last item in the name unless it comes at the end of the sentence in which case you should use a period (or question mark if it is a question). e.g. Is Oxford, England, full of clever people?

The main times when geographical names are composed of two or more entities are:

• between a village/town/city and a state, e.g. I live in Miami, Florida.
• between a village/town/city and a country, e.g. I live in Liverpool, England.
• between a county and a state, e.g. I live in Cook County, Illinois.
• between a county and a country, e.g. I live in Cornwall, England.
• between a village/town/city and a region, e.g. I live in Garsington, Oxfordshire.
• between a region and a country, e.g. I live in Tabasco, Mexico.

A classic example would be if you used an address in a piece of text, e.g. Eric Wimp, living at 29 Acacia Road, Nuttytown, eats a banana to transform into Bananaman.

The parts of an address should be separated by commas and it should be followed by a comma unless it appears at the end of a sentence.