Car rental

I would think so. It is 20 inches longer and a few inches wider than the tiny Fiat 500 we always get, so it is still pretty small.
Edit
And as said below you will be parking in lots outside of the towns, but smaller is still better as the parking spots can be tight.

Where do you plan to go? Be aware that the historical centers in almost all Umbrian towns are ZTL. You'll be parking outside. There's parking lots that will be plenty big. Assume anywhere within a walled town is ZTL.

Familiarize yourself with signage so you can avoid driving into a ZTL zone. We found ZTLs in Italy well marked and easily avoided. Look up driving rules as well. Italy has automated speed checks and assume there's zero tolerance for speeding.

We had a wonderful time driving in Italy, mostly in Chianti. Learn the rules and follow them. We got no tickets because we did our homework and used common sense.

Have a wonderful trip!

Just pointing out, if you find yourself trying to park in the streets of a small town of Umbria or Tuscany, you are probably racking up fines from automated cameras. Many towns have ZTL regulations to keep traffic out of town centers, in most places you park in lots on the outskirts of town and walk or take a bus into the city center.

Based on my casual observations in several trips, you’ll likely see more Clios than about any other car, so it’d be a good choice. Motor scooters take up even less parking space, and are quite numerous, but probably not practical for you to rent. Happy motoring/parking!

We will be in a rural area between Umbria and Tuscany for a month from mid-October to mid-November, so we will need a car. Would a Clio be large enough for five adults? We'll use the car to get from the airport to the villa and for day trips. Thanks for the advice to stay away from the towns. I think my husband has the notion that he can just drive into a town, park the car, and go on his way admiring all that the town has to offer. I'd never heard of ZTLs until I read another post, so I will definitely do my homework. But back to the original query: can anyone compare the Clio to American cars with which we are more familiar? Thanks in advance.

For comparison, the Clio is 3 feet shorter and 6 inches narrower than a Corolla.

Hopefully there is no more than 2 of you.

glassygal, when you reserve a car, you will select a class of car and will not be guaranteed a specific model, but you must also be sure to take luggage into consideration (and perhaps car seats, based on your other post). I would look at midsize and family size (those are AutoEurope's size designations--they are a popular company, recommended by many here and in other forums).
There are lots of different Clio models, but I think that one would be ruled out for your party given the need for luggage space.
Since you are usually parking outside town, I don't think you have to worry too much about car size. The first time I worried a lot about it, but the the second time, we rented an SUV in Puglia and it was fine.

The last 2 times we rented in Italy we booked a midsize car-(2 people) and got a small SUV-sorry can’t remember model

It was fine because you won’t be driving IN to any towns-assume they all have ZTLs and the parking is in lots outside the walls
We always make sure our accommodations have easy to access legal parking.

We have never received any tickets or fines 3 rentals in Italy, 2 in France
We did get a speeding ticket in Germany

Please do your homework
All drivers must have an IDP
And if it hasn’t been mentioned be sure you have a designated driver if you are wine tasting as the alcohol limits are much much lower than US

The Clio, and presumably other cars in that class, has a trunk volume of less than 9 cubic feet.

Can you get all your luggage into a Corolla trunk ( 13+ cubic feet) and use only 75% of the space?

If you are hauling the 4-5 adults mentioned in your other posts, this is not the car class for your group. (Or you will need 2 )

I cannot imagine you would be able to get a roof rack, so abandon that thought. ( Rental car co. not going to want the headache of potential roof top damage or liability issues with improperly secured stuff falling off)