Medici villas in Florence area

Actually there are 11 of them. I’ve visited all of them when I lived in Florence, but only few are open to the public inside. If you don’t have a car, the easiest to visit is probably Villa La Pietraia in the district of Castello. It is one of the few open to inside visits and it has nice gardens. The Villa di Castello is also near it, although I don’t think it is open inside (maybe by appointment) as it is the headquarters of the Accademia della Crusca, the national academy of the Italian language and grammar. Basically they are the ruling body of the Italian language, much like the Academie Française in France.
Both are along the bus line 28 to Sesto Fiorentino.
Not far from both is also the Villa di Careggi, near the University of Florence Medical School campus at the Careggi Medical Center. I’m not sure if it’s open inside for visits, I was only able to see the exterior, although that was decades ago. The tramway (T1 ) goes to the Careggi University Med Center, and from there it’s a short walk.
All others are somewhat harder to reach quickly without a car. Villa Demidoff in Pratolino is nice too with a great park, but you need an extraurban bus to get to it.

Hello Roberto, Many thanks for your kind reply. While in Florence we will not have a car because I don't want to drive in a big city! However after a few days in Florence we will be picking up a car to drive around Tuscany so we could visit the Medici villas outside of Florence that are worth visiting. Would you have an opinion as to which ones are "not to be missed regardless of location?". Thank you Roberto.

https://commons.wikimedia.org/wiki/File:Medici_Villas_Location-en.svg
That is a link of all the Medici villas.

I would say the best Villa Medicea to visit for you, since you don't have a car, would be Villa Pietraia, in the Castello district. The walk from the 28 bus stop to there is probably a pretty long one, but it wouldn't be too expensive to take a taxi, since it's within Florence's city limits.

The one in Poggio a Caiano, is also outstanding, but without a car is more challenging to reach.

The one in Pratolino (Villa Demidoff) has probably the greatest park. It's out of town, so if you are interested in visiting that one too, wait till you have a car, it would be easier.

But I would start with Villa la Pietraia, being so close. And it's free too.
http://www.polomusealetoscana.beniculturali.it/index.php?it/185/firenze-villa-medicea-della-petraia

Thank you Roberto. Actually after a few days in Florence we will have a car for seven days. With the car, do you have anything to add? Thank you!

I think the villas I mentioned should be more than enough. You don't want to go on Medici's overload. I'm sure while in Florence you will also visit the Medici Palace (Palazzo Medici-Ricciardi) and the Medici Chapel. Palazzo Pitti was a Medici's residence too. They bought it from the Pitti family in the 1500s and became their principal residence and later the residence of the Gran duchy of Tuscany.