How to reach Patrashttp://wikitravel.org/en/Patra
You may use Athens Airport or Araxos Airport to come to Patras.
Using the Athens Airport, then come to Patras:
Use the Suburban Railway System (Proastiakos) from Athens Airport (called "Eleftherios Venizelos") to Kiato terminal station (KIATO is a small city between Athens and Patras). The route duration is 1.5 h. At Kiato station take the (connected) bus to Patras (this route duration is again 1.5 h). Due to railway-lines construction, there is no train from Kiato to Patras.
The current total cost is about 25 Euro. Train is the recommended transportation, if the time-table found in the following link, fits well to your schedule:
Note that there is 5 min walk from Athens Airport to the Railway Station.
Right outside the terminal, at the arrivals level (exits 4 & 5), take the Express Bus X93 (departs every 30 min) to the Kifisos Intercity Bus Station. There, you have to catch the bus to Patras.
The route duration from the Athens Airport to the Kifisos Intercity Bus Station (called KTEL) is about 1 hour, depending on the traffic load (this bus-ticket costs 6.00 Euro - tickets-kiosks are located nearby).
From Kifisos Intercity Bus Station (central station for busses that run domestic routes all over the country) take the bus to Patras. Buses depart every 30 minutes, from 5:30h till 22:00h. The trip duration, taking an Express Bus to Patras, is about 2.5 h (this bus-ticket costs 20.60 Euro - go to KTEL ACHAIAS kiosk).
Please visit the following URL: http://www.patrasinfo.com/en/patras-athens-international-airport-by-bus/.
To come to Patras from the Araxos Airport, information is found at the following link: http://www.patrasinfo.com/en/araxos-airport-patras/.