Train from Rome to Sorrento

You need to buy your ticket at the latest before you board the train. So in theory it is perfectly feasible to just go to Roma Termina, buy a ticket for the next train to Napoli, and then just hop on. Trains do not sell out weeks in advance. They would be useless if they did.

However buying the ticket in advance, if you know when you will be travelling, can save you non trivial amounts of money.

Now to get from Rome to Sorrento involves a train to Naples, and a local service from there. You can now buy a through ticket on Trenitalia that covers both the high speed train and the local.

But Italo does offer a train+bus connection a few times a day, that gets you to Sorrento comfortably, on one booking. See www.italotreno.it
That would be my choice if the schedule fit.

Because the local travel issues are more complex than you may realize, I suggest you use the Search box top center. Especially for the Sicily continuation, which is more challenging. Do make sensible plans for being at your home-flight airport safely to check in three hours before departure. I suggest you buy or library-visit our host's "Rick Steve Italy" for a good overview.

There is no single train from Rome to Sorrento. You have to choose between cheap, flexible trains from Rome to Naples that take about 3 hours, and expensive, comfortable, Frecciarossa service trains. These have advance purchase discounts, but you cannot take a different departure, or change your ticket without a large fee. These take more like 1:20, but I didn't look them up. In Naples, you go downstairs on the escalator and buy a walk-up commuter ticket on the hot, crowded, gritty Circumvesuviana service, which has a line that terminates in Sorrento. Some people prefer to hire a car and driver, or a flat-fee taxi in Naples, because they find the jammed conditions on the Circumvesuviana so challenging.

As Wengen posted you can purchase the entire journey from Rome to Sorrento on Trenitalia now

https://www.trenitalia.com/content/tcom/en.html

Roma Termini to Sorrento Circumvesuviana
Change at Napoli Centrale -go downstairs for the Circumvesuviana ( local train)

Return from where?

It is because the circumvesuviana is not the most agreeable of services that I think the train+coach combination that Italo offers (in cooperation with ItaBus) is an interesting option.

You can buy tickets at the station minutes before boarding and there will be seats available at full (BASE) price. The advantage of buying early is that you can save money as there will be discounted fares available (for example SuperEconomy and Economy fares) which are limited in number for each train and therefore will be gone as you get closer to the departure time. If you buy discounted fares be aware of restrictions on the ability of changing dates/time or getting refunds in case of cancellations.
The Base price you see listed on the websites today will not increase on the day of departure.
www.italotreno.it
www.trenitalia.com
(note that the above two companies operate high speed trains from Rome (Roma Termini) to Naples (Napoli Centrale). Then from Naples to Sorrento you need to get on the Circumvesuviana metro commuter train. You buy tickets on the Circumvesuviana at the Naples station.

I appreciate learning about that unified purchase option.

This post is very much a matter of opinion: But it seems to me that being able to purchase the entire journey at Trenitalia is not entirely a good thing. To a traveler who has not made that route before, it creates the false impression that you are dealing with one, national agency, for the entire trip. And that the equipment and services would be roughly parallel.

But it's much more like buying an Amtrak ticket from Philadelphia to a hotel in northern Manhattan. The second ticket is for an urban transit agency that is even more starved for budget than Amtrak, has no luggage racks, and will have elbow-to-elbow standing room on most journeys. Of course, I'm referring to the New York City subway system, the only way to go by train from Penn Station to most of northern Manhattan.

Even when the second public transit agency is less rough-edged (say, for someone staying in Jersey City to save money on Manhattan hotels ... ), it's a disservice to believe that there is some real connection between the long-distance train company, and the Port Authority of New York and New Jersey Hudson "Tubes" (Penn Station to Jersey City), as they used to be called.

EDIT: Even though there are many budget-travelers on this newsboard, it seems clear that once people hear about the heat, savage crowding, some pickpockets and aggressive accordion-players, travelers elect to spend quite a bit of extra money for a car transfer from Naples to Sorrento, or to the Amalfi coast.

Note to precisionists: I'm aware the CIrcumvesuviana has overhead luggage racks. But they have even LESS space than overhead "luggage" racks on a long-distance bus! A soft backpack won't even go in there.

Hi. Thank you, all of you for responding so promptly. I appreciate all your thoughts. The comparison of the Circumvesuviana to the New York City subway made me laugh - because I live in NYC, so I understand what you're talking about. Now, I haven't looked into it yet, but if the italotreno.it arrangement involves a bus that is clearly more comfortable than the the Circumvesuviana, then it sounds like the way to go, unless the hire-a-car-driver or flat-fee taxi is not significantly more costly. It's also like in New York City: I could take the subway to JFK, but taking a taxi is just so much more comfortable and convenient, that it's worth it. And, finally, I will check out Rick Steves Italy, and Rick Steves Sicily too. Thanks again, and feel free to respond with any additional thoughts.

"But it's much more like buying an Amtrak ticket from Philadelphia to a hotel in northern Manhattan"

I think it would be excellent if that was actually possible. Buying tickets between random public transit stops is possible in many countries (Switzerland for example does this very well), and that way you avoid confusion.

Otherwise you get situations like in Spain where people try to find out how to get from San Sebastian to Bayonne and not finding anything because Euskotren is not in the system...

We're headed to Rome/Sorrento in a few weeks. We booked the combo of the Italo high-speed train to Naples (Afragola station) and the ITAbus from there to Sorrento. We are returning to Rome to spend a few days there before flying home, but we haven't yet booked our return tickets. We're toying with taking the ferry from Sorrento to Naples and then taking the high-speed train back to Rome. Haven't booked that yet but plan to do so before we even leave the U.S. as I've heard they can sell out.

Even though there are many budget-travelers on this newsboard, it
seems clear that once people hear about the heat, savage crowding,
some pickpockets and aggressive accordion-players, travelers elect to
spend quite a bit of extra money for a car transfer from Naples to
Sorrento, or to the Amalfi coast.
(Tim speaking about the Circumvesuviana Naples/Sorrento)

I'd say it all depends. We took the same journey as yours, Roma Termini/Naples Centrale, switch to the CV to Sorrento in March 2017, mid-afternoon. A little crowded, no problem. Then...because rained cats & dogs for three days in Sorrento, on a Sunday morning we took the CV to Naples, cab to the Architectural Museum--a must see if you're in the area--and then retraced our steps. Yes, on the way back to Sorrento there were some gypsy-like flute & accordion players making a racket, but I was seated and we just ignored them. Very much like an urban commuter train in the US. I'd take it again...during the day. Absolutely dirt-cheap.

Hey Jay, I'm not discounting your personal experience at all. It is fair to say that I was making a general observation (because of the way this newsboard gets "read"), not specifically for the OP's "mid-late April." But because for us, on a Monday in late May, 2014 (9 years ago), mid afternoon, it was all we could do to squeeze into an already full car on the Naples-Sorrento Cirvumvesuviana. We could barely keep our (large) bags in sight, while trying to avoid blocking the doors or aisles for other travelers, with maybe a fingertip or toe in contact with the bag. And it was absolutely swelteringly hot. Every square inch of the car floor was occupied.

Those scary (Ironica Typeface ... ) musicians couldn't ask us for money because they could not move within the car either! I grew up in NYC, and took the subway daily to high school and to summer jobs for years. I know what a rush-hour crowd is like, but this was really over the top. I'm sure you'll agree that Europe is more crowded today than it was in 2014.

Because we felt overcharged for our 15 Euro taxi to the Ambasciatori Hotel in Sorrento, it was easy to spring for a 95 Euro car service back to the train station, after our five nights in Sorrento. I admit we're older, and can afford it.

Hi - and thanks for these recent responses. I tend to agree with you, Tim, mostly because of our current circumstances - I'm older than I was back then, and can now afford that taxi ride from Naples to Sorrento and vice-versa. But, I do remember when I was younger and I couldn't afford it - so I understand under those circumstances, different options need to be considered. Thanks everyone for the different perspectives.

I am following and jumping in to ask another question if that is okay. We are doing a very similar journey. My family of 4 is traveling from Rome to Naples and then on to Sorrento but we will hire a driver for that leg. My question is I am also wondering if i should book tickets now for the train from Rome for first class seats? Are they worth it vs the other seats? I know its a very short ride. Do those seats sell out? Our trip is first week of September. Thank you.

RosaMaria, it would be best if you started new threads with your questions (I see that you've jumped in on another poster's thread) so that those posters don't get alerts for responses having nothing to do with their own trips. Make sense? :O)

That said, we've been perfectly comfortable in 2nd class and have never felt the need to spend more for the upper-tier carriages, especially for a journey of a little over an hour. Book ahead if you are sure of your trip and see a reduced fare that works for the day/time you want to leave Rome. Read the restrictions for reduced-fare tickets carefully.

Hi. I do agree a new thread is in order, but since the question is akin to what I had originally asked, I will share that when you make the purchase a couple of months or so ahead of time, as I did per the recos, there are some discounted seats, making the price difference between the 'classes' lesser. In other words, it's not that much more to get a better class ticket if those reduced priced seats are available.

Hey Jay, I'm not discounting your personal experience at all. It is
fair to say that I was making a general observation (because of the
way this newsboard gets "read"), not specifically for the OP's
"mid-late April." But because for us, on a Monday in late May, 2014 (9
years ago), mid afternoon, it was all we could do to squeeze into an
already full car on the Naples-Sorrento Cirvumvesuviana. We could
barely keep our (large) bags in sight, while trying to avoid blocking
the doors or aisles for other travelers, with maybe a fingertip or toe
in contact with the bag. And it was absolutely swelteringly hot. Every
square inch of the car floor was occupied.

Heya, Tim!

YES, by the time of our trip next April, I'll be 68 with a fresh hip replacement rather than the spry 60-year-old of 2017. IF I was going to the A.C or Sorrento (which I'm not), I'd avoid the Circumvesuviana, probably at all costs. I don't have the patience anymore to handle itinerant beggars who mask as musicians, and remark, 'oh, how funny'. I'd say F off, and they may hit me over the head with their accordion. No international incidents wanted!

Indeed, (hope not to hijack here) these advancing years have a definite effect on how I analyze my advance travel plans. Yes, there's going to be a ton of walking no matter what. But I really--because I can--fine-tune it to, well, how much walking? Because we love trains and plan to travel from Zurich down to Rome, taking the famed Bernina Express and stops in Chur, Varenna, Florence & Rome along the way, I'm fixated on finding hotels/AirBnbs within reasonable walking distance of the train stations, like a quarter-mile or less. It's doable. And the cheap walkup in Rome we stayed in 2017 was perfect and fun then, but would be quite claustrophobic to the 2025 me. So, yes, we spend more to breathe!