Fast train from Rome airport to Naploli Central Stayion

Which Rome airport? There are two, Ciampino (CIA) and Leonardo da Vinci–Fiumicino (FCO).
Ciampino has a bus to Roma Termini railway station, Fiumicino has its own station, "Fiumicino Aeroporto railway station".
You can look up train times and prices on the Trenitalia website: http://www.trenitalia.com/tcom-en
This will probably involve changing trains in Roma Termini station. Best not to buy tickets in advance, as you cannot predict when you will emerge from the airport, but the Trenitalia website will tell you what is available.

You may be better off just taking a direct bus "Fiumicino Express" from FCO airport to Naples (http://www.fiumicinoexpress.com/?lang=en).

Otherwise you'll have to take Leonardo Express (http://www.trenitalia.com/tcom-en/Services/Fiumicino-Airport) to get to the Termini train station in Rome and then switch to another train (look up schedule on Trenitalia) to go southbound to Naples.

Just go to the airport train station and buy tickets. You'll take the Leonardo Express train to Roma Termini station and change to a Freccia train to Naples. Don't buy ahead of time, you really don't know what time your plane lands and how long it will take to get through immigration with your luggage. There are usually about 2 fast trains every hour from Termini to Naples.

I don't know, pick your poison, although neither choice is bad.

Yes, there is the Fiumicino Express to Naples for around 20 E, but departures are every two hours. With Trainline Fiumicino/Termini, then Freccia train to Napoli Central, it might end up costing more (prob between 30-40 Euro in total depending on which train) but they run every 20-30 minutes from either point.

I second the bus option if the timing works. It appears it is a 3 hour drive. Prior to arriving @ FCO I checked the airport site for travel options to the train station. Postings also present the options. Know the schedule for Trento or Italo trains. Trento kiosks are everywhere and you will need euros unless you have that one CC that works at kiosks. Italo may have kiosks but I used the customer counter. Check their hours of operation. I could use my CC. I found the train to Napoli had lovely scenery. For the future I will start our trip in Rome for several days. I found the transfer exhausting. Therefore, I suggest the bus from FCO to Napoli. The route is highway and you'll be able to get some ZZZ's....

Fast Train tickets bought on day of service were 90 E x 2 plus transfer cost to the train station by bus. Not, cheap.

Not cheap? Gee, that's a pretty good price in my book. 14 EUR for the Leonardo Express and 45 EUR for the Freccia to Naples, per person. You'll be in Naples in 2 to 2 1/4 hours, departures are generally every half hour, but you might hit it at the wrong time and have an hour wait.

That's roughly the cost for 2 for a water taxi from Venice airport into Venice.

I wouldn't buy tickets in advance on the day of travel. Airplanes are unpredictable especially if the weather doesn't cooperate. Also if you arrive in the evening you need to specify how late. Fast trains don't run all night and neither does the bus.

For the purposes of this response, I'm assuming the Rome airport in question is Fiumicino.

For today, the last train connection shown on the TrenItalia website has a 9:53 PM departure from the airport and a 15-minute transfer at Termini. It would be essential to buy tickets for the full trip at the airport, because there might not be time to buy the ticket to Naples at Termini.

The best I can tell, the last regional train from Termini to Naples departs at 8:56 PM.

The last bus seems to leave Fiumicino at 9:55 PM.

Take into account the time you'll need at Roma Termini to buy your tickets to Naples. As far as I know, you can't buy them at the airport. Some ticket machines don't take cash and not all US credit cards work. There are always lines at the ticket counters . . . and sometimes at the machines too.

Because you are leaving in one week, advance Frecciarossa tickets are not likely to save you much, but avoiding the purchase line is worth something. But as noted, airport exit time is unpredictable. Are you sleeping in Naples? (The Circumvesuviana doesn't run all night.) If so, download the flat rate taxi fare sheet in case of arguments with your driver.

"arriving into Rome airport in the evening" leaves a lot to the imagination. What is the scheduled arrival time? Are you arriving from elsewhere in the Schengen zone so you don't have to clear customs?

And yes, we are assuming you mean the main Rome airport, Fiumicino.

Thank you and look forward to hearing from someone soon. Leaving in 1 week.

You're welcome. I'm glad to see you returning.

Please help us help you more by providing the details....

By the way, when you went to Venice you never posted a trip report. How did it go?

Trenitalia has a great easy to use app on which you can find schedules as well as purchasing tickets. Comprehensive and easy to use. When entering stations, use Fiumicino as origin, Napoli Centrale as destination. If you are checking from outside Italy, subtract the time zone difference (i.e. 6 hrs for EST) from the Italian time to get schedules for your projected departure.

I have bought tickets to other destinations at the airport train station, it's a Trenitalia station desk at the tracks. You can also buy Leonarfo Express tickets at other places in the airport, perhaps that was what Chani referred to.

I've never gone farther than Termini when flying into Roma. I remember buying the Leonardo ticket at a kiosk that didn't look like an official Trenitalia office. Thanks to Zoe for the info!