Cellular provider for Greek Islands?

Cosmote and Vodafone are the two main Greek providers. As a European, I don't need to look for another provider or worry about roaming charges, my phone automatically connects to one or the other. Both work well.

On the highly touristy islands with excellent coverage like the ones you are visiting I think you can choose either one, and you will easily find shops offering temporary plans. Note that Cosmote has just changed its brand name, it's now "Telekom".

Vodafone 25 days €16

With the Roamless app, you can make phone calls for a few cents per minute. And your spouse could use the app, login with your account and do that. She would need data, of course.

@travelerguy, David is asking for providers in case his wife wants to use her old iPhone which only supports physical SIMs. The roamless app only works on eSIM-compatible devices.

If you are flying into Athens There is a Vodafone stand in baggage claim at carousel 1. They will set it up for you
The €16 is calls and data 25 days.
You can then just top up if you are longer than 25 for another €16

Great info, thanks to all.

For this trip, we are bypassing Athens completely, flying from the US to Helsinki then onward to Rhodes, so that's where we will be getting devices set up. (No shade intended for Athens, we are simply focusing on the far southeast this time, and we're skipping Athens because it adds extra time and logistics...we'll get Athens and the Greek mainland on another trip, especially now since hometown Alaska Airlines now flies to ATH nonstop from Seattle!).

The roamless app only works on eSIM-compatible devices.

JoLui, thats not true. The only thing the app is for is to login to your account and see your useage, add cash, etc... and make cheap phone calls. I just took a very old Galaxy S9 phone which has no esim capability, has no sim installed, and is in Airplane Mode (but does have wifi on). I installed the Roamless app, logged in with the account I use for my personal phone. Then I dialed my wife, and it worked fine. The dialing screen said it would cost $ 0.04 per minute.

Once the Roamless esim is installed, it will work on that phone. The phone doesn't really need the app to use the Esim. Of course the app is needed to check balances, add money, etc...

The OP's spouse could just install the app, and login with the OP's account, and make calls.

Of course, the spouse would need data to do this. That could come from wifi, another esim, or even from the OP's phone (if the OP turns on Wifi Hotspot on his phone). The easiest thing would be for the spouse to make her own account, add $10, and have data and phone calls while away from wifi.

Take a look at Viber.
But like what’s app except you can buy credit to make calls to people who do not use what’s app etc.
It’s very widely used in Greece.

@travelerguy, I must have missed some details, the roamless website isn't very clear, they just state in the overview that it "works on eSIM-compatible devices."

So, indeed, if it works, it could be an option. just need to check and compare the rates.

JoLui, it is tricky to find the calling rates. I could not find them on their website, but their site says to use the app. Open the dialer, and there's a purple box with "rates". That will show you a zillion countries with their per minute rates. You are right, you need to check the rates, as they vary from 4 cents/min. for USA and Italy, and a lot of Europe, up to $10-$15/minute or more for some small, remote countries.

And I should add that this is for voice calls only, you cannot send texts with the in-app dialer unless you subscribe, and pay a monthly fee, for a "Roamless Number".