Flights from Cinque Terre to Seattle

Pisa is the closest airport. I would aim to make only one connection on the way back, such as at Paris or Amsterdam (Delta has direct flights from Seattle and partners with several European carriers). If booking a flight either directly through Delta or another airline search site, try a "multi-city" trip plan, into Venice and home from Pisa, or else home from Genova or Milan. I prefer an Amsterdam connection over Paris, if possible, so I recently chose to fly from Milano Linate in order to get that connection, versus flights from Milano Malpensa were connecting in Paris (again with Delta).

I have done this 3 times. Once I flew from Genoa, which involved getting up VERY early to get the train to get to the airport, since I spent my last night in Vernazza.

The other 2 times, I flew out of Pisa, but both times spent my last night in Lucca. Very easy to do, about 25 min train ride from Lucca to Pisa, then you catch the shuttle bus to the airport. Less nerve-wracking than hoping there is no problem with the trains that day from Vernazza, and getting to the airport in time.

Delta also has a daily flight from Pisa to New York JFK (June through August only).
If I'm not mistaken that flight leaves from Pisa late in the morning or even past noon, therefore you could even stay your last night at the Cinque Terre and take a train to Pisa the morning of departure.

i echo Charlotte's post. We stayed a week in the CT area and then took the train to Lucca where we stayed for a couple of days until our flight back to the US. We went through Heathrow, starting in Pisa. The train ride from Lucca was easy to Pisa, 25 minutes, short shuttle ride from train station to airport. The Pisa airport is pretty small and easy to get around but it is pretty crowded and not real comfortable awaiting your flight. Its not a great airport for lounging. I'd be a bit more nervious if on the day of our flight we had left the CT as we had to change trains at La Spezia. I'd go the same way if I were returning to the CT!

Milan has lots of flights and is about 2 1/2 to 3 hour train ride from Vernazza which is an awesome place.

Many thanks to everyone who replied. Greatly appreciate your taking the time to share your experiences and recommendations.