Trenitalia

The age old question. If you buy an advance discount ticket and your flight is delayed or there is a big jam up in immigrtaion, you lose the ticket and have to buy a new one. Why not just buy it when you land? The full fare price is not that great and the discounts are not that big unless you are several months out.

Trenitalia sells everything as e-tickets when you buy online. Budget about $50 for standard class if you buy on the spot from a ticket machine.

You can also buy train tickets with your phone, using Trenitalia's Trenit app, which I found very handy on my recent trip to Italy. If you will have a working phone in Italy, you can buy your tickets for Florence as soon as you get on the Leonardo Express to Rome. (Note that ticket sales may end for app purchases some minutes before the train departs, so if a train leaves at 10:00, don't expect to buy them with the app at 9:50.) Of course, buying at the last minute means paying full fare for the ticket. You can pay for tickets in the app using a US credit card or your Paypal account. Note that you can't register with Trenitalia as a US citizen (if you are one) and will have to buy as a guest each time, but I got used to that after buying tickets several times.

One reason to use the Trenit app is to save the time of finding a ticket machine at Termini (if you don't have a chip and PIN credit card, you won't be able to use the machine unless you have cash) and maybe save time for a tight connection. And sometimes there are lines at the ticket machines, which might be as long as the lines to buy tickets from a person at a ticket counter. The Trenit app also shows platform numbers and delay information, so you can get off the Leonardo Express and know which platform to walk to for the Florence train, without even looking for a reader board. Even if you don't buy the tickets with it, the app is useful for the delay and platform info.

Jen,

What time does your flight arrive at FCO?

As others have said, it's generally not a good idea to buy advance tickets to connect with an inbound flight. If the tickets booked are on an express train and you miss it, the tickets are worthless and you'll have to buy more at full price.

You may or may not be transiting through Roma Termini. Some trains route through Roma Tiburtina via the FR1, and its important to know which train you're using when you leave the airport. With either the LE or FR1, you MUST validate tickets prior to boarding the train or risk hefty fines!

There are a few direct Freccia trains from FCO to Firenze SMN every day, and it would be much easier if you could connect with one of those. As I recall there's a direct departure at 11:08 but I'd have to verify that.

I'll expand on this later when on a regular computer. It's more difficult to post on a 4" screen.

As mentioned above, there is a risk in buying discounted tickets (SuperEconomy and Economy fare) online ahead of time. Those fares are restricted (non changeable and non refundable), therefore you lose your investment if for whatever reason you miss the train you book.

When I land in Rome (and I always have to go straight to Florence after landing), I just buy at the Fiumicino Aeroporto train station on the spot. I pay full price (Base fare), about 50 euro one way on standard class (2nd class), but at least I don't have to fret on the plane.

Be aware that now all trains from Rome to Florence stop at Tiburtina after departing from Termini, therefore you don't need to take the Leonardo Express to Termini (which is more expensive). At the Fiumicino Aeroporto station you'd take the regular Regionale train that takes you to Tiburtina (for half the price), and there you intercept the Freccia to Florence. It's just as fast that way because the Regionale takes the rail bypass on the north side and goes straight to Tiburtina without going through the Termini mess. Tiburtina is also a better station to transfer (fewer people, no gypsies trying to handle your luggage and steal your wallet).

Be aware that there are two high speed trains that depart to Venice (and of course Florence) directly from the Airport. They depart at 11:08 and 15:08. If they work for your time of arrival, they wouldn't even require you to change trains. Just hop on board at the airport station, and they take you straight to Florence without having to get off your arse at all.

check schedules and prices here:
www.trenitalia.com
Use station names in Italian:
FIUMICINO AEROPORTO
FIRENZE S.M.NOVELLA