From Athens to the Airport 4:00am

We took bus line X95 from Syntagma Square to the airport in October and it was a lot less expensive than a taxi! Several websites say this service operates 24 hours per day, but I'd prefer to verify in person.
Good luck.

We always arrange with our hotel to have a taxi take us to the airport. They have a set rate (I think it's 40 euros) ... which we feel is well worth it at that time of the morning, with that long day of travel ahead.

I can confirm with 100% certainty that the X95 bus operates 24/7/365, leaving Syntagma Square every 20-30 minutes. The fare is €3.2. Buy your ticket from the driver and validate it in the ticket machine inside the bus. There is ample space for baggage storage inside the bus.

The bus is 24 hours according to Rick's guide. Syntagma Square is a center of civil unrest when it occurs, but doubt that will be an issue at the hour when you will be catching the bus. Be aware that strike activity can put buses, taxis, etc. offline at short notice. Flights are usually cancelled when there is a general strike, but the worst case is when the flight goes but your chosen mode of transit is on strike. We flew out of Athens in late October and to be safe booked a private car for around $225 which our hotel (a major American chain) assured us would run even in case of strike. There are cheaper private car transfers, but they were not reassuring with regard to whether they would run in case of a strike. (Think of the cost of rebooking when you miss your flight both United and Lufthansa said we would be out of luck if we missed a flight for this reason). Anyway, when it became clear that there would be be no taxi strike that day, the hotel let us switch it out to a regular taxi the night before departure. It ended up being around $80-90 counting the night premium. I would be nervous relying on the bus if you also need to take the taxi to get to Syntagma square, because that means two possible points of failure. i.e. if either buses or taxis are on strike, you are in trouble. A good web site to follow for strike information is http://livingingreece.gr/strikes/ The good news is that it's not typical for both taxis and bus to on strike at the same time; if they are chances are it's a general strike and the flights will be cancelled too (unless the courts rule it illegal for air traffic controllers to participate.) Our arrival and stay in Athens was strongly affected, but our departure was not. Here's hoping you have the same good luck! I advise having a plan B in case your first choice is affected by strikes.

Just an FYI- I've been taking the X95 back and forth from central Athens to the airport for the past 3 months or so and have paid 5 Euro per ticket.

Perhaps stay at the Sofitel Hotel right in the Athens airport and walk to your flight. Not cheap though.

Katie-Thanks for the X95 fare correction. I forgot that it had been increased.