Where to stay in Italy for 3 months Spring 2024?

Does dual Italian/US mean you have dual citizenship? If so, you won’t need to worry about the 90-day Schengen Zone law.
If you plan on getting around using public transportation Florence makes a good base. Day trips from Florence by direct bus or train include:
Siena – 1h 15m bus
Milan (Milano Centrale) – 2h train
Padova (Padua) – 1h 45m train (reserve tickets for the Scrovegni Chapel before going).
Verona – 1h 45m train
Pisa – 1h 30m train
Lucca – 1h 30m train (get an early start)
Bologna – 45m train
You can also fly in or out of Florence too.

I'd consider Padua for one of your bases. It has good transportation connections and I find it a nice place to be. Lodging tends to be comparatively inexpensive there.

If I were to pick 4 places to spend an extended period of time, sticking with Central and Northern Italy, I would start with the most southerly and move north and consider

• Perugia as a base to explore Umbria all the way to the coast with many smaller towns (Gubbio, Spoleto, Spello) close by. Perugia, though, is a transportation hub and not overrun with travelers, IMO
• Arezzo as a base to explore Tuscany. Florence and Siena are more inundate with travelers so Arezzo might be a little less manic and afford a glimpse into real life
• Ferrari, Modena, or Reggio Emilia: Close to Bologna, Ravenna, Padua and more in the Veneto but again more livable perhaps than the major tourist destinations
• Trento or Bressanone if your stay is sufficiently into May or even June. Near the mountains if not quite in them, access to a glorious landscape and entirely different culture. I would also look at Merano although the connectivity might be less than ideal. There is a train station but most everything has to go through Bolzano. Bolzano off-season might be pleasant as well.

Venice workedfor us when we stayed for eight weeks. Twice.

Alessandria
Modena
Bergamo
Trento

I would suggest Tuscany. Consider Sienna or Lucca.

If by "spring," you mean as early as early March, I would first spend time in Venice because it will be less crowded before Easter.

Then, supporting some of the cities/towns that other people are suggesting, the most livable and well connected cities I've stayed in for at least a week (and wanted more time in) are Padua, Florence, Perugia or Spoleto, and Modena or Bologna. Remember that what matters for judging the size and feel of a city is not the total population but instead what the historic center is like --- none of the places I've listed except maybe Bologna feel like a city once you are in the center.

And what I've had good luck with is finding a place to live within the old center but out towards its perimeter and away from the heavily touristed spots --- better food and less expensive apartments and more normal stores like hardware stores and butchers. Still easily walkable and/or with good buses to the train stations. Even Florence has plenty of such areas.

If you had a car, I could suggest some other places to live with more access to nature and, actually, even better food than any of the places I and others have named. And if southern Italy was OK with you, I would have said Lecce in Puglia.

Here’s cities where I have stayed, and I just travel by train. I removed the largest cities and the smaller village type, ones that weren’t my favorites and others that didn’t meet your criteria.

(Lake Maggiore) I always stay at Stresa, but you may want a more residential town.
Bergamo
Verona
Cremona
Mantova
Perugia
Torino
Parma
Arezzo
Lucca
Padova
Ferrara
Grosseto
Trento

My suggestion would be to Google “Italy train map” images which will show you the train lines. From that visual, you can look up each city that is on the main train lines to see which ones appeal to you the most.

For instance, I really enjoyed the ambiance of Mantova with the multiple piazzas where locals congregated in the evening. I walk around in the evening in cities, and this was striking in the amount of people enjoying being together. If you like to bike, it’s also a great area! But, I hesitated to mention it because I wasn’t sure there’s enough train connections for you compared to a city like Verona.

Ferrara, I forgot to recommend Ferrara!

Well Pescara is on a high speed train line. It's considered central Italy...maybe not by northern Italians but by Abruzzese and by the map...and Abruzzo has a fantastic quality of life. Worth a look-see in my (biased) opinion

I am also dual citizen US/Italy and have enjoyed long stays in Italy for years. In the past, I have based in Florence for access to great transportation options for day trips as well as long weekend trips to other countries. However; recently, rents in Florence have skyrocked so last year I spent 5 months split betwen 3 locations....3 months in Pistoia (a short train ride from Florence so I could still visit and also a quick trip to the beach in Viareggio); 1 month in Genoa and 1 month in Chiavari on the Ligurean coast. The issue with smaller towns is definitely tranportation...trains can be infrequent at times so definitely something to sort out before you decide on a location. Also, after spending so much time in Florence, I was not expecting a 3 hour shut down middle of the day which is a smaller town thing. Caught me off guard a bit. In any case, I'm going back next year for a multi-month stay and will stay again in Pistoia...slower pace, less crowded, decent train and bus transportation etc. and better rent rate! Enjoy researching your options!

For me Verona, and there's no second choice. It's big enough, it's small enough, it's culturally deep, it's connected in every way. close to most every type of natural environment.

Agree 100% with Mike from Boston. Perfect place to use as a base while checking out other areas.

When I have traveled alone to Italy I always take a one or two week Italian class. It's a way to connect with other travelers and of course get better in Italian. I've met friends who I ended up connecting with later in my trip. And while you are taking classes you have a ready made "friend group" if you want to be around people to go on day trips with or dinner, etc.
PM me if you'd like reviews of some of the schools I have attended.

Second the Lago Maggiore suggestion. We lived in Verbania for 2 1/2 years and traveled by train to visit other parts of Italy and Europe. The train is about a 15 minute bus ride from the city centers, but never an issue. We loved being on the lake and near the mountains. 1 1/2 hr train to Milan.

We thought it was much less expensive than Stresa, across the bay.

Happy to answer questions via PM