And if so, how do you get one?

See this site:
https://it.usembassy.gov/u-s-citizen...ation-driving/

Any AAA office.

Hi J,

See https://www.aaa.com/vacation/idpf.html for your application form.

Yes, it is required, and now you know how to get one, so do so.

It means that the poor cop who does not understand American can at least see the usual words in the right slots in a standard form. Yes you need it.

To be 'technical' it isn't required to rent a car but it IS required to drive it legally . . .

exactly, this isn't a car rental company requirement, but an issue with the government/police. It doesn't have anything to do with understanding "American", it would be required for many other foreign languages, especially ones written in a different alphabet, and there are thousands of different-looking drivers' licenses in the world also with different info in different places. It's required for Canadians, also. It isn't required if you have a license from an EU country, though, in Italy.

You can get it by mail if you can't go in person.

This is the info for how to get one if you are Canadian
Driver's Licence

Janis and Cristina, recently people have been reporting on Tripadvisor that they were refused rental cars in Italy because they didn't have an IDP. Here is an example from three years ago. It may not be universal, but don't take chances.

https://www.tripadvisor.co.nz/ShowTo...ome_Lazio.html

Well I think the OP has got the message... end of discussion?