Maritime Southeast Asia fit a lot of good locations for city-states due to the fact they are located on islands.
- Puerto Princesa on Palawan
- Cebu City on Cebu
- Zamboanga in Mindanao
- Manila in Luzon (Technically due to pejorative of
Imperial Manila, it can be argued that OTL Philippines is a ruled by the city-state of Manila)
- Sandakan and Kota Kinabalu in Sabah
- Ambon, Ternate and Tidore in the Maluku Islands
- Island of Bali
Also in Insular Southeast Asia, Phuket in Thailand comes to mind
East Asia
- Hainan
- Dalian (aka Port Arthur)
- A number of different islands on the coasts of China could be good spots for city-states although its too many to mention.
- Ryukyu Islands (aka Nansei Islands)
- Jeju
- Busan
- In general a number of islands in South Korea and Japan also makes possible spots for city-states to emerge as well.
Pacific Islands/Oceania
- Independent Hawaii
- Wellington in New Zealand
- Island of Tasmania
- Perth and Darwin in Australia
- New Caledonia
- Fiji
- The Samoas
- Guam
- Port Moresby in the PNG
- Through colonialism a number of different islands can become good locations for settler city-states to emerge in places like the Bismarck Archipelago or the Solomon Islands.
Russia
Petropavlosk-Kamchatsky
North America
- San Francisco Bay Area
- Los Angeles
- Vancouver Islands
- Juneau in the Alaskan Panhandle
- Anchorage