Rail or Tour from Rome to Pompeii

VAlexCross, there is no "bullet train" from Rome to Pompei. There is no direct train at all. You can take a fast train from Rome to Naples but there you'd have to change to a local Circumvesuviana commuter train.

It takes slightly over an hour from Roma Termini to Napoli Centrale, where you walk over the adjoining Garibaldi station to catch the Circumvesuviana. You will need to purchase tickets for that train when you get to Naples (they are very inexpensive) and they must be validated before boarding. Same for the return trip to Naples.

If you are traveling during the warmer months, the Campania Express - which is a little more comfortable train - also makes runs from Garibaldi to Pompei, Ercolano, Sorrento, etc. and has fewer stops along the way. The only issue with that one is that it has far fewer runs per day - only 4 or so - so to make the best use of time, the Circumvesuviana is probably your best bet.

You'd want to exit the Circumvesuviana or Campania Express at Pompei Scavi Villa dei Misteri station, and it's about 30 minutes or so from Naples. The station is right in front of the main entrance to the excavation. This is the way I'd do it so that you could spend as much time as you wish to exploring the site: it's HUGE and can easily take a big chunk of a day without seeing it all.

You could also have dinner in Naples before taking a fast train back to Rome. :O)

There is now a new option getting from Naples main train station to Pompeii. Citysightseeing runs a shuttle bus that picks you up right outside the station and goes direct to Pompeii. This is not a guided tour, just transportation, but it's much more convenient (and probably safer) than the Circumvesuviana train.

Because the Frecciarossa rail service is so much faster than highway busses, you might consider 3-month advance discounts (no changes, no refunds) for the Rome-Naples segment. This is an ambitious plan for a same-day runout. You might use the Search box to read about past inquiries on that specific topic. Unless you want it organized for you, there is no need for a tour company. Many people do this independently all the time. Be prepared for sun and heat in high season. Don't confuse the Trenitalia stop in Modern Pompeii with the Circumvesuviana stop just across the street from the Porta Marina entrance to the ancient city, the "Scavi". If you don't know what I'm talking about, you need to do more research :-)

Have you considered Ostia Antica, rather than the long mad dash to Pompeii?

I recommend saving Pompeii for a trip when you can spend a few days in the region, i.e. Sorrento, or Naples

Don't confuse the Trenitalia stop in Modern Pompeii with the
Circumvesuviana stop just across the street from the Porta Marina
entrance to the ancient city, the "Scavi".

There's really no way to confuse them as Trenitalia trains do not go directly to the scavi nor to Sorrento. This is the current Circumvesuviana schedule with listed stops:

https://www.sorrentoinsider.com/en/naples-to-sorrento-train-schedule

Don't use the Trenitalia website for Naples - Pompei as you don't want to go the TOWN: there is another entrance to the excavation from there but it's a bit of a walk from that station.

Have you considered Ostia Antica, rather than the long mad dash to
Pompeii?

Definitely something to consider. It's much closer and will be less expensive to do.

Kathy, what can I tell you? People confuse them here at least once a month. And some people argue that Trenitalia is better, especially for those staying in the paradise that is Salerno (Ironica typeface).

LOL, Tim; I gotcha there. Pompei to/from Salerno is a 'lil different animal. :O)

Thank you all very much for your comments and suggestions!