Delphi is 180 km northwest of Athens, a journey of about two and a half hours by car via the Athens–Lamia motorway and then inland through Arachova. Buses run daily from Athens's Terminal B (Liossion) — the journey takes around three hours and runs several times a day in both directions.
The road from Arachova into Delphi is dramatic and winding, with the mountain rising on one side and the valley dropping away on the other. If you are driving, the road continues west through Galaxidi to Nafpaktos, a worthwhile extension if you have time. Delphi has no train connection.