15 days in Italy, Rome, Florence, Venice... how long in each?

1 night is not near enough time for Venice
3 would be the minimum, 4 is better

Florence needs at least 3 nights, add a night for each day trip planned

You can never have enough time in Rome

You might add in an easy to get to stop like Orvieto-give it 2 nights

Are you flying IN and OUT of Rome?
If so put all your Rome nights at end of trip
Head to either Florence or Venice on arrival day

I count 14 nights
Rome 3 since you’ve been there
Venice 4
Florence 5 with 2 day trips
Other like Orvieto 2

Venice needs at least four nights, more would be better. I can’t begin to understand staying only one night there!
Skip Cinque Terre.

You could spend weeks in Venice and not exhaust the possibilities.

Overnight flight? If so…

15 arrive AM, head to Florence
21 to Venice
25 to Rome to enjoy time with niece
29 fly home

That gives you 5 non-travel days in Florence, 3 non-travel days in Venice, and 3 non-travel Rome days.

Probably your friend who suggested the short time in Venice didn’t give herself the chance to really enjoy it. Venice is magical! Purposely wander and get lost. Go to Suso and have their wonderful Manet gelato - yum! Take a vaporetto out to Burano to see the brightly-colored homes & shops. I would give it 3-4 nights.

From Florence there’s a lot of options for day trips. Modena, Parma, Siena, (interested in a Montepulciano/Siena type minivan tour?), Ferrara, Ravenna’s probably too far, or Lucca are just a few ideas.

I like the idea of staying in Orvieto on the way back to Rome. It’s nice to stay in one of the smaller towns in the evening.

And from Florence the daytrip possibilities include Siena ( a 70-minute express bus ride away) Lucca ( a 75-minute train or bus ride) and Pisa ( 1-hour by train)
Pisa and Lucca are only 30 minutes apart by train so the two could be combined in a marathon daytrip from Florence.

Venice 3 nights
Florence 6 nights (including day trips)
Rome 7 nights

Rome has much more to see than the other two cities. Of course, from Florence you can do day trips to Siena and Pisa.

Thanks all for the great ideas. It is an overnight flight, arriving at 11:00am in Rome, I was also thinking about heading directly to Florence and doing all of Rome on the end. I'm assuming even if we're delayed a bit, we should be able to get a train to Florence that day and still arrive not too late. It will be an exhausting day but maybe it's better to get the travel in all at once. Do all trains from Rome to Florence go through Termini or is there a more direct route from FCO? Should we consider flying since we're already at the airport? I don't know how far the nearest airport is to Florence central area but I do like the idea of arriving by train right into the center.
From everyone's responses it sounds like we need to give Venice three nights. I'll also look into Orvieto. I know we could easily enjoy many days in Rome but since we're planning to return to Italy a lot and Rome will most likely be our starting/end point most of the time, I'm ok with only a few nights in Rome this time if we decide to add Orvieto.

It sounds like Cinque Terre isn't high on people's list. Is that because of time of year, weather, crowds? Just curious. We could save that for a separate trip I guess.
How about places to stay in Florence and Venice? Any recommendations for hotels/apartments or preferred neighborhoods?
Thank you.

There is one direct train from FCO to Florence at 1:53
That might actually work for you but you don’t want to purchase tix in advance in case of delays

Otherwise take the Leonardo Express to Termini and transfer there to the next fast train to Florence
Station is Firenze SM Novella

Get the Trenitalia app and you can use it to purchase tickets once you’ve landed

Or you could head to Orvieto to start your trip, it’s close and a nice place to get over jet lag
From there you can head to either Florence or Venice

I personally don’t love Venice. Like Venice but I think 3 nights is more than enough. We stayed two nights in Orvieto last month. We also stayed two nights in Siena. Really liked both. We also went on a day trip to Naples. The fast trains are really easy to do. Even the regular trains are easy.

We were visiting our daughter who was studying in Rome. Since it was our 4th trip to Rome we did a lot of different things. The first three were all part of different Rick Steves tours.

If you want ideas for Rome just let me know. Enjoy

The idea of heading right to Orvieto on your arrival day is a good one. You'll be able to buy a ticket on arrival day at a considerably lower cost than you'll run into if you go to Florence.