If we’re admitting not only cities but also regions or countries (for which the -ia ending is quite common), then you’ll get a lot. In the Americas alone, you have Bolivia and Colombia. Plus the District of Columbia. In Africa, Cecil Rhodes got two Rhodesias named after him.
U.S. states which meet the OP’s criteria (named after an identifiable historical person and ending in -ia) are Georgia, Virginia and West Virginia.
Let’s not forget Alexandria, Alexandria, Alexandria, Alexandria, Alexandr…
The guy liked naming cities after himself.
To speak to the OP directly, I don’t know if Greek is the original etymology of the -ia suffix in place names, but it definitely shows how old the tradition is. If you want to aggrandize yourself as ancient heroes and conquerors once did, you take your name and slap IA on the end.
It is. Was used in the form -eia in Ancient Greek, with a meaning that would derive a feminine variant of an existing noun (polis is feminine in Greek). See the Wiktionary article (which gives another example for its use in city names, Caesarea): -εια - Wiktionary
The Romans, who liked to integrate Greek culture into theirs, modified the suffix to -ia to fit their pronunciation.
Like lots of stuff on the internet, take two facts and draw an incorrect connection between them.
John Batman founded a settlement upstream on the Yarra River which drained into Port Phillip Bay in New South Wales in 1835.
From 1835-1851 this village was the population centre of an administrative district of New South Wales known as the Port Phillip District, and was governed from Sydney.
In 1851 the colony of Victoria was founded, with the town of Melbourne as capital.
John Batman died in 1838 in Melbourne, after the village he founded was renamed in 1837.
Another example are the umpteen places named Victoria that can be found all over the Commonwealth. Of course, in this case -ia is already part of the name of the person in whose honour these places were named; it’s not a suffix added to turn the personal name into a toponym.
And while we’re talking about made-up place names using the -ia suffix, I’m also throwing in Brasília, Brazil’s planned capital city founded in the 1950s. Not the name of a person, of course, but it applies the -ia suffix to get a neologism.
That confused me just the other day when I read about an institution in Victoria, Australia called the “Victorian” something-something. For a second I thought it meant Victorian-era before I realized it meant the state. Of course Victorian is a legitimate adjective to refer to things in the various Victorias, but it will always look like an era to me on first read.