Plane to US from Cinque Terre

The closest intercontinental airports with flights to the US are Milan Malpensa and Rome Fiumicino.
Both are over 4 hours away by train.

There are two airports that are closer: Pisa or Genoa (about two hours from either).
However both have intra-European flights only, therefore you would need to change planes somewhere in Europe.

Unfortunately neither airports has frequent connections to London Heathrow with British Airways (British is AA partner), but give it a try from Pisa. Pisa has one British Air flight in the middle of the day headed to London Heathrow. In my experience it’s generally too late for a meaningful connection to the US, so I find it useful only if I want to spend a few nights in London before coming back to America.

The two nearest airports of size are Genoa and Pisa, each some 2+ hours away (albeit in opposite directions). Pisa had a better selection of flights/times when we were there. In our instance, we flew from Pisa to Munich, for a Lufthansa non-stop back to SFO. Alternatively you could train to Rome or Milan for direct flight to US and plan connections (from DFW or Miami, if American Airlines).

I’ve done this before. Take the train from Vernazza to Milano and fly back from Milan Malpensa. If you have the time, get into Milano Centrale in the afternoon and see the Duomo, Galleria, even DaVinci’s Last Summer (book a reservation for that well in advance). Fly out of Milan the next morning.

Use a search engine like kayak.com for all options as the combinations are endless. Try Genoa, Pisa, Milan, Rome, Florence, as you departure airport. What is your arrival airport in Europe? Be sure to book round trip or multi city tickets and not one way tickets.