Sicily itinerary - thoughts?

Cefalu is very nice, but very small. If you're not planning to hang out at the beach, I think you'd do better to spend those 3 nights in Palermo and day trip to Cefalu.

Select the number of nights in each place based on what you want to see. With a rental car I wouldn’t want to drive in Palermo either, so Cefalù makes sense. We stayed in Monreale and took the bus into Palermo. Between Monreale and Cefalù we stopped at Caccamo castle that was pretty impressive and only a couple miles off the main road.

With an early start you could visit Taormina between Cefalù and Catania and not make it a separate day trip.

Some will say you need more time in Palermo, but with limited time, a day there makes sense to me.

I'm in the "there's a lot to see in Palermo" group. I wouldn't want to be limited to just one day trip there. It will help if you get to Monreale on a separate day.

Palermo has so much to see and it's a fantastic city.

Here's two of the trip reports I did:
https://community.ricksteves.com/travel-forum/trip-reports/trip-report-palermo-before-starting-a-rick-steves-sicily-tour-day-1

https://community.ricksteves.com/travel-forum/trip-reports/trip-report-palermo-before-starting-a-rick-steves-sicily-tour-day-2

I have been to Catania twice - and while there is a bit to see there - the WW2 museum stands out and the fish market is interesting - I wouldn't give it 3 days on your tour.

You also don't seem to have Villa Romana del Casale on your trip and it was absolutely the best thing I saw on Sicily. The mosaics there are incredible. I've never seen anything like it in volume, color, variation and storytelling. https://whc.unesco.org/en/list/832/

I would take a night off Catania, and make it an overnight in/near Agrigento. An overnight there would give you the space to see Villa Romana and Valley of the Temples on your way to Palermo/Cefalu. These are really the two headline sites on the island, and I’d consider them essential. Most folks seem to view Taormina as an overblown touristy place here, and prefer Ortigia. So, I would probably not try to day trip it.

I’d also go Palermo for three nights, and day trip to Cefalu (if that even.) Palermo is great, totally underrated city. Cefalu is nice, but with the limited time you have I think it gets bumped down the pecking order. Another day trip from Palermo is Monreale, if you can manage it (hours/days don’t always cooperate.) You won’t need a car in Palermo itself, but driving in and parking it somewhere won’t be too difficult. If you did day trip out, I would use public transport and leave your car behind. Both Monreale and Cefalu are very accessible by bus/train.

There is a lot to see in Palermo. Only a day trip? You need 3 days to see Palermo and Monreale.

Cefalù can be seen in a few hours. You can stop there on the way to Palermo (I parked here and it's a guarded lot) or you can take a day trip from Palermo (1 hr drive).

May might not be beach weather, so I don't know if I would spend 3 nights in Cefalù. If you stay in Palermo, you need to stay outside the ZTL or even in Mondello (which has a beach, if you must stay at a beach).

I don't care for Catania much, so I would probably stay there just the last night near the airport. You can add those days to elsewhere, or spend a couple of nights in Giardini Naxos (under the hill where Taormina is), and get even more beach time.

ARe you flying into Palermo and out of Catania, or both in and out of Catania? If you start in Palermo then I agree with all of the above recommendations to base in Palermo rather than Cefalù. I would rethink and reallocate nights from Catania and Cefalù. Do you. know what order or general direction you will travel in? That depends on your entry point to Icily. In Palermo you will not need a rental car. If you are flying both in and out of Catania maybe just concentrate on the eastern side of Sicily and save Palermo and surrounding area for a future trip. If you concentrate on the Catania side you can consider Taormina, Savoca, Mt Etna area and wineries, Catania, Siracusa/ Ortigia, some of the Baroque towns and even a possible night in Agrigento to see the temples and the Villa Romana del Casale. Catania is another place where a car would not be necessary.

I like Pat's idea. You really don't have a lot of time and transiting between Palermo and Siracusa will eat up half a day at least. However, if this is your one-and-only trip to Sicily, I would not sacrifice Palermo, and just day trip to Cefalu (nice duomo, but not as nice as Palermo or Monreale--you can do it in 1/2 day if you hustle) and eat the travel time. And, from Palermo you can day trip down the coast to Trapani, the salt pans, Mazara del Vallo, Agrigento, Marsala, and Erice in addition to Cefalu. (We spent nearly a week in Palermo and based out of Trapani for 11 nights and kept ourselves plenty busy day tripping to all the above-mentioned destinations.) Castellammare del Golfo is nice, too. Obviously you don't have that much time, but you see you could easily spend your entire time in Palermo as well. The eastern side of Sicily is equally interesting, just different. We enjoyed Catania more than most, but unless you're using it as a base for day trips, you could cut a night and spend one day there and one in Etna or Taormina. Or stay in Siracusa and day trip from there, although Taormina gets barely beyond a "meh" from me--billions of tourists by day and plenty of ruins elsewhere. If you decide to ditch Palermo and Cefalu, you could spend all your time in Siracusa and use it as a base for Catania, Etna, Taormina (longer trip but doable), Noto, Ragusa and Marzamemi. Everybody goes to Noto, and the architecture is lovely, but it is essentially a one-horse town. Research which of the day trips are most important. Personally, I'd choose Ragusa. As it stands now, with even just one day trip, you would completely shortchange Siracusa.