I don't have to tell you about the toilet situation in Floville.
First of all, in Italy ALL toilets are considered public, in the since that you really cannot enforce the bathroom for paying customers only. It is polite to buy at least a glass of water or something if your bathroom going is too obvious.
THere are good toilets in the COIN and RINASCENTE departments stores, not to mention the EDISON and MARTELLI booksotres - but please no more VIVA MEXICO and ANTI USA graffitti!
Be alert, almost all the toilets in all the big train stations are pay toilets and the fare for the one way ride is now 70 cents!!
There is also a public toilet inside the Mercato Centrale as well as in one of the side streets off of the Mercato San Lorenzo (follow the signs).
About the only public restrooms in the entirety of Florence are at the train station, and those are almost worse than no facilities at all. If you're staying in town, you're in luck. If you're out and about and suddenly develop the need, hope that public "johns" have been refitted, reinstalled or reopened. Many that I saw were closed due to their contracts not being renewed. My only hope was the train station.
Update: I've since been told (after this posting) that pubs are required by law to offer public restrooms. Thank you, utttz.
Like many European cities, there are not a lot of public bathrooms (WCs, Toiletten) available. I did see a couple signs for WCs around the town, usually in out of the way places. So it is always a good idea to use the bathrooms when you find them in a place you are patronizing – in your hotel, in the café, in the restaurant, in the museums. If I really must stop into a café for the bathroom, I try to purchase something there – they usually keep this service for customers only.
If you find a public bathroom, there may not be any paper or washing facilities and you may have to pay to use the bathroom. It is always a good idea to have change, tissues, and hand sanitizer with you when you travel in Europe.