train from London to Florence italy

Trainline is my favourite. Out of curiosity I had to look, that's a 17 hour trip with 2 or 3 changes. No judging, but I'm curious why you're thinking of train over plane?

It can be done in 13 hours if you leave London by the 8 am Eurostar, with train changes at Paris and Turin. You also have to change stations in Paris, from Gare du Nord to Gare de Lyon. You can do that with the RER D. That will cost you another 1.90 EUR per person.

The train from Paris is about 7 hours to Milan or Turin. Then you can hop a train to Florence…about 2 hours from Milan, not sure about Turin. I would suggest watching for the return of the overnight train from Paris to Venice. I seem to recall it stopped in Florence. It stopped in 2021 during Covid. Read the ‘man in seat number 61’ for information. (London to Paris is easy).

Book London-Paris from www.eurostar.com and book Paris-Florence from www.trenitalia.it for the fastest option, which is London-Paris-Milan-Florence. But you can also take the route via Switzerland if you like to add some time there.