Patras eats well for a Greek port city, with the harbour end of town having a decent concentration of seafood tavernas and the area around Georgiou Square and the main shopping streets offering a broader range. The city's size and its university population mean you get genuine variety — not just tourist Greek food, but regional Achaian cooking and the full range of Greek street food done properly.
Fresh fish from the Gulf of Patras is the thing to order: the local catch includes sea bream, sea bass, octopus, and the various small fish that are best eaten simply grilled. The tavernas around the old harbour (Psila Alonia area) are generally reliable. Inland from the port, the streets between Georgiou Square and the market district have trattoria-style Greek tavernas with long menus of mezedes and grilled meats — the kind of place where you order several small plates and work through them slowly with wine. Patras produces its own wine, though the Achaia Clauss winery northeast of the city is most famous for Mavrodaphne, a sweet dark fortified wine that goes well with cheese or at the end of a meal.