The new Athens Eleftherios Venizelos International Airport lies around 15 miles to the east of the city center. It opened in 2001 as part of the infrastructure improvements in preparation for the Olympic games.
As you'd expect with a major European capital city, Athens airport handles flights from dozens of major carriers, including budget flights with the likes of Easyjet. Some routes are only seasonal, however, so it's best to check well in advance that flights from your airport are operating during the football season. For a handy flight checking tool, we recommend Skyscanner.
Another option is flying to one of the Greek islands and getting an internal flight with Olympic Air, the Greek national airline. Some fans choose to spend a cheap week on a package deal and get an internal transfer to Athens for the game, which can often work out cheaper than flying direct.
The easiest way into town is by Metro, which costs €6. Group tickets are available, providing some discount on the fares. The airport is on Metro Line 3 (Blue) that connects with the major stations at Syntagma and Monastiráki in the city centre.
Don't forget to validate your ticket before travelling - unvalidated tickets will be subject to a fine if caught out by the inspectors.
A taxi into the city will set you back around €35 - beware of the usual unlicensed taxi operators touting for business at the arrivals hall and use a metered, official taxi.
Alternatively, suburban train services run from the airport, at the same cost as Metro tickets. This runs from the airport to Larissis Railway Station in Athens, from where you can change to Line 2 of the Metro for connections to Omonia and Syntagma stations.