There are several parking lots that surround the town, so it shouldn't be difficult to find parking although in the summer time, they do get a bit full. There there are visitors coming and going continually so be patient and you'll find a spot!
San Gimignano is very organized with their parking and you can find up to the minute information on availability in each lot by checking with their official link: San Gimignano Parking
Arriving in San Gimignano from the SOUTH
If you're coming from Poggibonsi, you'll arrive on the southern end of San Gimignano. The closest lots are P1 Giubileo and P2 Montemaggio.
P1 Giubileo is the first one you find, right at the first roundabout. It is the largest and cheapest (€1,50/hour and max per day is €6), so we highly recommend this one as the best parking lot in San Gimignano. It has 5 disabled parking spaces (always free with permit). You can also park here overnight for €1 (between 8pm and 8am). From here you can walk up quite easily to the main entrance into San Gimignano.
P2 Montemaggio has 3 disabled parking spaces, but costs €2/hour with a max per day of €20. Between 8pm and 8am, cost is €5. It is the closest to the main door but it also quite often full.
Arriving in San Gimignano from the NORTH
If you're coming from Certaldo or the north in general, the closest parking lots as you arrive into town are P3 Bagnaia Superiore and P4 Bagnaia Inferiore. They are practically right next to each other and are right below the northeastern edge of the town. They both cost €2/hour with a max of €15 per day. Cost between 8pm and 8am is also €5.
If you arrive with a motorcycle, there are parking spaces in P2 and P3.
If you buy a museum pass to the San Gimignano Musei Civici, you'll get €1 discount off your total parking fee.
Parking is paid with cash at the ticket machines before you leave.
If you have any questions, you can write to parcheggi @ comune.sangimignano.si.it