We will be going to Sicily in September and would appreciate suggestions on flights to Palermo
and out of Catania. Leaving from Atlanta.
Thanks
Check Google flights: https://www.google.com/travel/flights and https://www.skyscanner.com/ then book with the airline if it’s not too expensive. It's always best to book on the airlines website in case something goes wrong.
You can also use www.Kayak.com, in addition to Google flights and sky scanner as suggested above.
Use the Multi City option
Going Enter from ATL to PMO on the date you want
Returning from CTA to ATL on the date you want.
The most likely solution that will come up is with Delta/ITA Airways, which are partners with the SkyTeam alliance.
You can also buy separate tickets using a low cost airline, for example from Rome Fiumicino airport (FCO). In that case search from ATL to FCO round trip.
Then using Skyscanner or a low cost airline (like RyanAir) search from FCO to PMO.
If you travel this way on separate tickets make sure you have plenty of cushion between flights in case you flight from/to ATL is late. Flying the European low cost airlines is cheap, but it has some risks.