Fiumicino has one official left-luggage desk, run for Aeroporti di Roma, if you need to drop bags for a few hours, a full day, or longer while you explore Rome or wait out a long layover.
Location and hours
The luggage storage desk is in Terminal 3, international arrivals, near the bus station. It's open daily from 07:00 to 23:00.
Pricing
€10.00 (VAT included) per item per 24-hour period. You pay when you collect your bag, not when you drop it off, and no advance reservation is needed.
What you can store
Standard suitcases, backpacks, and similar travel bags are accepted without issue. As with any staffed luggage service, expect restrictions on hazardous, perishable, or high-value items — if you're unsure whether something qualifies, ask the desk staff directly rather than assuming.
Alternatives if the desk is closed or full
Since the service operates only in Terminal 3 and only within set hours, travelers arriving in Terminal 1 outside those hours will need to either cross to Terminal 3 landside or consider a lounge or hotel that offers luggage holding as part of a paid stay — HelloSky, for instance, can hold bags for guests using its landside rooms.