Carry on

Alitalia web sites says one small back pack in addition to suitcase - no size specified.

If you can get it under the seat you'll be fine. We just flew British Air and Easy Jet. I was really worried about Easy Jet as I read all these posts about how strict they are, and my wife and daughters suitcase was about 1" too long. Bought the tickets that allow 2 carry ons and no one scrutinized our bags on the 4 flights we took.

Here's the Alitalia website page on hand baggage: https://www.alitalia.com/en_us/fly-alitalia/baggage/hand-baggage.html

In that it says:

Alitalia also lets you bring an accessory of your choice from the following:

Briefcase
Laptop computer
Handbag/Small Purse
Small Backpack

The usual principle is that your carry-on goes in the overhead bin, and the personal item/accessory goes under the seat in front of you. While they don't specify size or weight for the "accessory," if it can go under the seat it's probably fine.

I think "small backpack" doesn't mean "tiny little thing that barely holds a wallet," but more like a regular school backpack that's not overstuffed. A "large backpack" would be one of those massive camping ones. Your personal item would have to fit under the seat.

I have flown Alitalia. On the flight to Italy, the electronic box for the mini-movie chair screen was under the seat. This left me with almost no leg room. So, while you can take a pack/purse in addition to your carry-on, I recommend that you carry the bare basics in it in case you need to compress your pack. Think wallet, light squishable jacket, first aid kit, tissues, important documents, etc..

Good point, Sun Baked in Florida. Next time, you can check www.seatguru.com for the specifics of whatever airline seat you have and get a heads up on whether the foot room is compromised.