Itinerary Update for May-June 2027 (somehow, I deleted my itinerary...here it is!)

In an earlier post you said you didn't want to drive very far upon landing. Even from Shannon, Cashel is a 90-minute drive. OTOH, I don't see anywhere else you could fit it into your itinerary.
Staying in Cork gives you day trip options for both Cobh and Kinsale and puts Blarney on your way to Kenmare. Plus, there are things to see and do in Cork. I think my earlier suggestion was to take the train to Cork and pick up the car on your way out (if you're flying into Dublin).
The biggest issue I see with this itinerary is that you have yourself finishing your trip in just about the furthest location from either airport with no time to return.
FWIW, Donegal is an easy add-on to a trip to the North. If you drop that from this itinerary and finish in Sligo (which doesn't need 3 nights, IMO), you have a straight motorway shot to Shannon, or you could overnight in Athlone, which is only a little out of the way back to Dublin, depending on where you're flying in/out. Or you could add in Newgrange with two nights in that area before flying out of Dublin.

I agree with G3rryCee that you don't need 3 nights in Sligo. While we enjoyed our 1 night in Sligo, our visit to Newgrange and Knowth was far more interesting and awe-inspiring. I would drop a night or two in Sligo and really try to fit in Newgrange. For us, visiting the inside of the passage tomb at Newgrange made us feel very privileged to be able to see this. And we loved Knowth, too! If you go, definitely include Knowth. The site is jaw-dropping when you first see it with the large tomb and the 19 smaller tombs scattered about.

Yes, my frustration is thinking we will be doing a lot of driving if we make a loop from Dublin and back. Maybe I am trying to cover too much in this 3-4 weeks...is it possible to get from Dublin to Cork to Dingle to Aran to Connemara to Sligo to Donegal and back to Dublin, adding in the sites like Cashel, Newgrange, etc. with a reasonable amount of driving and assuring we are slowing down enough to genuinely experience Irish culture, spend time in local communities, and enjoy the tucked‑away places that don’t show up on most itineraries?

That's a pretty good start for an itinerary. You still didn't mention "what you like/enjoy". We "matured" in our six Ireland trips from all one night stays to mostly two night stays, so if you pack light, don't worry too much about frequent moves - we even stayed three nights in several places! We find a lot of our favorite places are "between towns" so the moves come pretty naturally. We really thrive on good trad music sessions, ruined castles, and Neolithic spots. A few observations, although I hate to mess with what looks to be a nice plan:

Three nights in Cork City will allow a day-long train trip to Cobh. There's some nice Cork City walks (although the signage is mostly missing). Don't overlook the fact that three nights usually means two days. Also, make sure you go to Sin e for music and the Market.

I'd favor Kenmare over Killarney, as Killarney can get busy, although May/Jun is a good choice for the tradeoff between crowds and regular trad sessions.

On Dingle peninsula, make sure you go to the new Blaskett Museum near Dunquin. The boat from Dunquin is the shortest and might be the more reliable, from a weather angle. Very nice walk about the island.

Doolin is a great base for the Burren. If it's Wednesday, make it to McDermotts for Blackie O'Connell on the Ullian pipes.

The ferry from Galway (Rosseveal) is much larger and a shorter trip, so go to Aran via that way to avoid weather cancellations. A both ports offer a diversion to the Cliffs, if you want to avoid the crowds up top. You can drive to the ferry or get a bus/ferry package from Galway. One full day on the big island is adequate, but two nights might be needed depending on your ferry choices. The island "transforms" when the last day-trip boat evacuates all the visitors. Also a good value for Aran sweaters.

In our swing through the northwest, we only stayed one night each in Clifden and Westport and didn't feel cheated.

We liked Donegal Town but Sligo is supposed to be nice too (we'll be there next May), too late for any feedback.

We stayed just two nights in Dunfanaghy. A day trip to Tory Island (or an overnight) might justify another night in the area. Make sure you go to the Workhouse along with other interesting places.

Reconsidering so many options...can we include a trip to N Ireland by flying into Dublin and leaving from Shannon (or vice versa)? How many hours/miles (Km) roughly are we looking at to do this? Is there any part of the trip we might consider using public transportation to decrease the amount of driving (just considering options). If we make a trip to Inishmor, we will be paying at least 2 days of car rental and not using the car...ideas to alleviate this, if any? Does it make sense to stay in Westport and Clifden or would one be a better base?

Cork City is mentioned as a base...would that be recommended over Kinsale or Cobh?

As far as what we enjoy...simply wandering — stumbling upon tucked‑away gems, cozy cafés, quiet harbors, and paths we didn’t plan on. We enjoy experiences that let us move at a comfortable pace: historic sites to explore, scenic hikes that don’t require hours of climbing, relaxed bike rides, and days that leave room for spontaneity. For us, travel isn’t about rushing through a checklist — it’s about presence, connection, and letting a place reveal itself.

Many thanks for all the responses! Our trip is beginning to take shape with your suggestions!

With respect, OP, your description of your travel style (slow pace, meeting the locals, hidden gems, spontaneity) and your itinerary (a fast-paced checklist of RS-recommended places) don't match at all, IMO. I suggest starting with a list of the places you want to see and the things you want to do. Place them on the map to determine what areas (not what towns) would make good hubs. You are not required to stay in a place you have already heard of or that is mentioned in RS books or on the Forum. I doubt very seriously that you will meet any locals in Kenmare, for example. Maybe if you're there early enough in the season, but my experience is that it is overrun with American tourists. Google Maps (or the map on your preferred booking site) can show you what accommodation is available in the area you are focussing on.
For each hub, add in 1-2 days (minimum) for settling in, wandering, bike rides, whatever. You will quickly see that you can't fit it all in 4 weeks, so then you cut based on your priorities. When you have that done, you'll probably start to see a route, and from this you can determine where to fly into and out of, where to pick up and drop off the car, etc.

I don’t see a lot wrong with your itinerary. You may just need a few tweaks. However I would say to definitely give yourself 4 weeks if you can. I happen to love driving and don’t find it difficult to drive in Ireland - your situation may be different. So moving locations with an estimated 2 hour drive every few days works fine for me.

Your beginning seems to be the trickiest part, including us not knowing what time you arrive. Honestly, it includes backtracking but you might look at arriving at Shannon (departing from Dublin) and head from Shannon 1 hr to Doolin to begin. Then head to Westport, down to Clifden, then Dingle, etc.

What I see is that your last 3 listed stops are so much further north and seem to fit geographically better with a return to North Ireland (and Newgrange) since you mention a future return. That might lead me to cut them. Plus you need a night near whatever airport you leave from.

Another better thought might be to fly in to Cork, rent your car there, add a night so you can include a day to Cashel, and then begin your drive south and heading north. Kinsale, Cobh, and Cashel are all possible day trips by public transportation from Cork, if you don’t want to drive them as soon as you arrive. I myself have not looked at car rental in Cork, but others have mentioned doing that. Doing it this way wouldn’t put you behind the wheel immediately when you have jet lag. You could then make your loop including the north and return from either Shannon or Dublin. The long drive from Dunfanaghy to Dublin (or Shannon) Airport would be easier to manage at the end, if you have a whole day and can schedule in stops.

You might then have: Cork-4 nights; Kenmare-3 nights, Dingle-3 nights, Doolin-2 nights, Aran-2 nights, Clifden-3 nights, Westport-3 nights, Sligo-2 nights, Killybegs-3 nights, Dunfanaghy-2 nights, airport-1 night, for a total of 28 nights. Just a thought.

To the OP, you can include Ireland and Northern Ireland in a 3 to 4 week trip. I know, because we did it with 23 nights on the ground. We flew in and out of Dublin. We didn't go to Cork, however. This is our itinerary, which worked for us. Maybe it won't work for you. My husband did all the driving; he loves to drive, and he did not find it stressful at all except for The Sky Road in Clifden because it was foggy and drizzly that day. But we emerged unscathed!

Dublin (3 nights), Kenmare (3 nights), Dingle (2 nights), Doolin (1 night), Galway (3 nights with a daytrip to Inishmore), Clifden (2 nights), Sligo (1 night), Derry (3 nights with a daytrip to Inishowen Peninsula), Causeway Coast/Bushmills (1 night), Belfast (3 nights), and Dublin Airport Hotel (1 night). We stopped at Newgrange on the way from Belfast to the Dublin Airport.

Staying in (or near) Cork as a hub would allow spoke daytrips to Cobh and Kinsale. We actually did that from Macroom, west of Cork, but we were petsitting for friends in their house, so we had a reason to be based in Macroom. It’s a nice village - Rick Steves mentions it in his guidebook, but he assumes you’re stopping off for lunch on your way to/from other places. Out in the direction of Cobh, we also had an extremely nice lunch at Ballymaloe House, and people stay there, too. Nearby, Ballycotton was a nice visit.

Finding parking in Kinsale is a particularly challenging effort, although spending the night, when daytrippers have departed, could be enjoyable.

Doolin or Ballyvaughan could be nice bases for The Burren, although we stayed in Lisdoonvarna - highly recommended!

We’ve visited the Aran Islands on two separate trips, taking ferries the first time, and flying Aer Arran the second. Both trips, rough seas cancelled or postponed several ferries, but the planes flew regardless of the weather. I’d take the plane, no question, for a third trip. We stayed on Inishmore two nights, and left our rental car at the tiny airport between Galway and Clifden, which would be right on your general route.

You probably have very good reasons for the locations and times after Clifden (where we stayed 3 nights), but for what it’s worth, on our 2018 trip, after Clifden, we:

• Stopped for the Killary Fjord boat ride out onto the scenic fjord, west of Leenaun. Had steamed mussels onboard, while gliding past the lines where they grow the mussels.
• Spent the next night and two days on Achill Island, northwest of Westport (not 2-3 nights)
• Passed through Sligo (quick stop in town), and spent 2 nights staying in Donegal.
• Up to Dunfanaghy for 2 nights
• now in Northern Ireland, stopped off in Londonderry/Derry enroute to Bushmills for 2 nights. Visited the Giant’s Causeway from there.
• Guided walk on The Gobbins Cliff Path (another one-of-a-kind adventure), on the way to 1 night at The Old Inn Crawfordsburn, east of Belfast. It’s more than 400 years old.
• The next morning, we skirted Belfast at morning rush hour (didn’t actually visit Belfast that trip), on the way to Trim, Ireland for 3 nights. We visited Newgrange and other sights from there.
• Turned in rental car at the Dublin airport for our flight home.

If you arrived in Dublin, how about waiting to get your car until you take a train (or bus?) to Cork, and then start driving from there? Rock of Cashel on the way to Cork.