How to spend 4 days in S. Ireland?

When will this be?

Drive from Dublin through the Wicklow Mountains to Glendalough. From there to Wicklow. Have lunch.
Then off to Killkenny. Stay the night.

Up early and on your way to Dingle. Stop at the Rock of Cashel then take the N74 to Dingle. Stay in Dingle. Enjoy some craic at Foxy Johns ( hardware store and a pub). Loved my seafood chowder at Harringtons. Drive Slea Head. Go early so you don’t get caught behind the tourist busses.

Don’t miss the Gap of Dunloe. Hike, take a trap. Killarney National Park is lovely.

@robert

End of Sept.

If you want to maximize your time in the Southwest (Dingle, Kerry, etc) I'd suggest booking one of the cheap, direct, RyanAir flights between Dublin and the Kerry airport near Killarney - there are two per day in each direction. There are rental car outlets at the airport there that would make it convenient to tour the area at your leisure without having to use up a lot of your limited time criss-crossing the island just to get there and back.
We usually base ourselves somewhere along the corridor between Castlemain (15 minutes from the airport) and Glenbeigh in order to stay clear of the congestion around Killarney town while still being central for easy excursions to Dingle, Killarney NP, the Ring of Kerry, the Gap of Dunloe, and the very pretty Skelling Ring Road.
By the end of September the crowds of summer have departed and Killarney becomes a better option as a prospective base.

Kilkenny, Cork, Killarney, Kerry, Dingle are all interesting places, but with only four days you really do need to cut back a bit on the list. Identify what your priorities are - and why you have identified these places. Are you wanting the buzz of a large town like Cork, or the scenery of Kerry? There isn’t on single location that would work for all of those as you would end up spending a lot of time in the car getting to the different destinations. Don’t underestimate distances in Ireland. They may not look big ion a map but will take a lot longer to drive than you might expect. Driving in much of Ireland can be quite slow.

You could quite easily spend all four days around Killarney/Dingle as there is so much to see and do from both of those places. Have a look at the list of ideas for Dingle here.

Killarney - obviously there is the drive round the Ring of Kerry (don’t miss the ring forts of Cahergal, Leacanabuile and Stague). There are also the Cliffs of Kerry with its stunning coastline, or explore Valentia Island. There is Muckross House and the traditional farms., a boat trip on Lough Leane, or a jaunting car ride along the Gap of Dunloe. There is Ross Castle, Torc Waterfall and Ladies View...

Take a trip south through Kenmare to Glengarriff and talkje teh ferry across to the tiny Gainish Island, before finishing the day at Bantry House...

Good suggestions here. Wasleys suggested deciding between city and country.
I agree, my preference is the countryside. I would skip Cork this time. Also, Killarney itself was quite cumbersome with people and in getting around the town. We stayed the night in Kenmare which is a delightful town and near access to Ring of Kerry. Again Wasleys has great suggestion, in my opinion. As so the others, of course.

I would spend the first day toward Wicklow and Glendalough then probably stay in Kilkenny. That’s not a lot of driving but there is much to see. Next day would drive somewhere around Killarney (not much help, I know). There is so much to see around Killarney and it may be doable to work Dingle in for the next days.

Robert’s idea of flying to Kerry airport is great and then you could concentrate on the SW- Kerry, Dingle and other points

Not sure I have added much here - just some thoughts.

Enjoy your trip!

I would spend the first day toward Wicklow and Glendalough then probably stay in Kilkenny.

I'm not sure what's in this area but since it's been mentioned 2x, sounds like a good plan for Day 1. So maybe leave Dublin early morning, plan to sleep in Kilkenny.

Day 2 - Ring of Kerry/Killarney (should we stay in Killarney?)

Day 3 - Dingle peninsula? (stay where?)

Day 4 - ???? then back to Dublin.

We're excited to do a "road trip" and driving/stopping will be half the fun, so we'll skip the flying.

That doesn't give much time to see anything in Kilkenny.

The drive from Kilkenny to Killarney is going to take around three hours. The Ring of Kerry is 3.5-4 hours to drive PLUS any stops you make on the way.

Don't bother to relocate to Dingle - spend two nights in Killarney and drive from there.

Be warned this really is a road trip and you aren't going to have a lot of time to stop and enjoy the sights...

we're mainly interested in scenery/nature. Wouldn't mind a cute town to stop and have a meal in though.

Is a full day each for Kerry & Dingle sufficient? I was thinking yes, and so I would just need to figure out what to do on Days 1 and 4 as we're driving to/from Dublin. Could also allocate half of Day 1 and 4 to them. So we'd have 1.5 days at each. And the other half of those days dedicated to the drive.

Could also possibly start the night before Day 1, depending on my son's schedule.

What about this itinerary I found?

Friday - leave the capital, traveling southwest towards County Kerry. An unmissable highlight along the way is the Rock of Cashel. Once home to the High Kings of Ireland, this group of medieval buildings is set on a spectacular outcrop of limestone. After continuing through the mountainous terrain separating Cork and Kerry, you’ll arrive in the town of Killarney, home to Ireland’s first National Park.
Driving time: 4 hours
Driving distance: 189 miles (305 km

Sat - Today’s adventure takes you on a 28-mile (45 km) drive to the world-famous Ring of Kerry. Considered one of the most spectacular locations in Ireland, this route will offer you dramatic landscapes of rugged coastline, golden beaches, picturesque villages, and green mountains.
After a long day of sightseeing, driving, and hiking, you'll head back to Killarney for the night.
Driving time: 1 to 1.5 hours
Driving distance: 28 miles (45 km) to 41 miles (65 km)

Sun - Dingle is your destination today, as you explore this dramatic peninsula littered with archaeological and historical wonders. Your first stop is Inch Beach, famous for being the place where an inch is 3 miles long. Take a short walk along its golden sands, then head west to the edge of Europe, also known as Slea Head. Feast your eyes on breath-taking scenery of its rugged coast, windswept beaches, and the magnificent Blasket Island, before ending your day in the colorful seaside village of Dingle Town.
Driving time: 1 hour
Driving Distance: 40 miles (64 km)

Mon - head back to Dublin. Different route than on way down?

That is a much better itinerary and gives you time to relax and enjoy Ireland. On Day one there is also the ruined Hore Abbey on the edge of Cashel that would also be worth stopping at.

The driving times for both Ring of Kerry and Dingle Peninsula are very optimistic. Depending on how many stops you make, ypou could easily spend the full day on each.

It does make sense to go back a different way to Dublin. I would suggest a northern route. Take N22 and N21 to Adare, one of the prettiest villages in Ireland - do a google image search - with thatched cottages. It's about 90km, so allow 75-90 minutes drive. It is possibly a good place for coffee.... Buy a picnic lunch here.

Then skirt round Limerick onto the N7 to Nenagh. Now head cross country picking up the R438 and R357 heading to the wonderful early Christian site of Clonmacnoise, on the banks of the River Shannon with its round towers, ruined churches and crosses. This is about 120km and although not busy may be slow to drive, so allow a couple of hours for the journey. You could easily spend an hour or more wandering round the site. From memory there is no cafe on site but it does have a picnic area, and would make a lovely spot to eat a picnic.

From Clonmacnoise head to the M6 and M4 back Dublin - This is about 130km and will take just under two hours, depending on how busy it is.

This is the long way round but will give you some different scenery.

We loved Kilkenny. Rock of Cashel was interesting, but I think I'd take Kilkenny if I needed to choose. Definitely plan on a full day outing for each of the peninsulas.

Could we squeeze in a few hours at killarney Nat'l Park at some point? What about the morning of day 4 before we head back to Dublin?