Time needed in Athens Airport between island flight and international flight home

Ya -- if everything works. For me, that is too many eggs in one hat. I probably would come to Athens the night before and without question on a much early flight that day to Athens. What is the plan B if the 3.20 pm flight is delayed or cancelled? It happens !!

Is it one ticket with the same airline (or code share)?
If so you are covered even in case of delay, because they would rebook you on the next available flight at no cost to you.

2h1/4 is really the minimum. You will have no safety margin.

If it's the Aegean flight A3 335 which departs from Chania, Flightstats reports it delayed very often, sometimes by almost an hour.

https://www.flightaware.com/live/flight/AEE335

Go to Athens the night before your flight.

Thank you all for your responses! I've already booked my non-refundable stay in Crete, so I would lose a substantial amount by going to Athens the night before my flight BUT per your suggestions I am definitely going to take the earlier flight to Athens which is scheduled to arrive at 10:20 am, which would give me a 7 hour cushion. Assuming all goes well, any suggestions on things to do around the Athens airport for a few hours? I'll be traveling with my 3 adult children. Thank you!

There isn't much to do within walking distance of the airport other than shopping. There is the Retail Park nearby which is accessible by taking one of the express buses (X95 which goes to Athens center for example) from the departures level.

https://goo.gl/maps/g3rjBsaQ13CqLQxA7

But after going through security at the airport you will find an area with plenty of shops, restaurants and bars which should keep you busy while you wait for your flight.

May I ask for further advice from experience Island to Athens travelers?? (Let me know if this should have been posted as a separate question.)

We will be flying from Santorini back to Athens, then back to the States. Will an overnight at the airport be sufficient assurance of catching an early afternoon US-bound plane out, OR, is it better to arrange the trip to have several final days back in Athens?

Obviously, unprecedented conditions can happen, but I wonder if it is usual for an entire day of Santorini to Athens flights to be canceled ? If that happens, we would want the additional Athens stay as a buffer. If it is not usual for multiple flights to be canceled between Santorini - Athens, the itinerary lays out much better to just do one airport overnight.

I can't see that these flights would be booked on one ticket. I will try that if possible. I'm looking at Aegean Airlines for the island hop. Trip is in late June or first days of July 2024.

Thanks for any thoughts or experience you can relate!

Many experienced travellers to Greece suggest you get out to your first island on day of arrival. Jet lag does not seem to be so bad on an Island. Leave Athens to the end of the trip so you are already adjusted to how things go in Greece. Doing Athens last means you are on the mainland before your flight home.

We were on a flight from Naxos to Athens. There were Americans, Brits, French and South Africans planning to connect that day for their return home. The flight was delayed 3 hours. None of them made their return flight and they were all frantically trying to rebook.

We were flying back to Athens for our return flight the next day.
Stuff happens and its good to have a plan for what you are going to do if you miss a connection.

If you intend to visit Athens, it is best to do so on the way back from Santorini (or another island).

As stanbr points out, it's always better for travelers from the US / Canada / Australia to fly to the island they want to visit as soon as they arrive in Athens, and save the visit to Athens for the end stay.
With this principle, no problem in the event of delay or cancellation of flights between the island and Athens just before returning home.

That being said, regarding Santorini-Athens flights you can safely plan a Santorini → Athens flight the day before your return flight to the US.
While there may be delays or cancellations, to my knowledge it is extremely rare that you will not be able to have a flight on the scheduled day.

Moreover, the vast majority of European travelers take a return flight home from Athens on the same day as the Santorini → Athens flight. Provided you allow enough stopover time in Athens this is not a problem, at least from Santorini where flights to Athens are operated by Airbus or Boeings.
This is not the case from Naxos or Milos or Paros where the flights are made on "small" ATR turboprops which are much more subject to cancellations in the event of bad weather.

In any case there is always a minimal risk, but probably with less consequence with a return flight to Europe.

Note that with ferries it's not the same story.
It may happen that there are no ferries two or three days in a row (due to weather conditions).

When I am on an island and I return to Athens by ferry, I always take this ferry at least 3 or 4 days before my flight home. (I admit that it's also because I like hanging out in Athens).

Thanks, JoLui for relating your experience. this is a new route for me so I had no idea what the "norm" might be.

I've seen the advice about going directly to an island and leaving Athens to the end of the trip. I am considering that. Thanks for reminding me, Eleanor.