Trouble renting a car near Tralee/Castlemaine - is it possible to Uber?

Unless in larger cities car rental agencies are closed on Sundays.

Things changed in Ireland during the Celtic Tiger years but one constant remains, church on Sundays.

Uber operates differently in Ireland.
https://spoketravel.com/does-ireland-have-uber/

Traveling is about understanding differences, and not assuming that what you have in the States you’ll find in other countries.

Ask your host about the best way to get around. Pretty certain they’ll have the answer.

Slainte

Really appreciate it. It hadn't even dawned on me that the place might be closed on Sunday. But even on Monday it looks like the car rental place won't have any automatic cars available.

Is it possible to make due in Castlemaine with taxi service? We had been hoping to make trips to Killarney and maybe the Ring of Kerry but I'm worried we won't be able to without a car rental.

Sorry can’t properly answer your question about taxis as I’ve always rented a car. IMHO the BEST way to see Eire.

Was born when Truman was in office so learned how to drive a stick shift.

Automatics aren't that readily available and therefore cost more.

If you can make your way to Killarney you may be able to rent a car from there on a Sunday by special arrangement.

Where are you arriving into Tralee from? As stated above, rental agencies in smaller towns may close on a Sunday. Have you tried Kerry Airport? They may open on Sundays. You'll definitely be better off with a car to tour Ireland, relying on taxis will be restrictive and cost a fortune!

Looking at your posting history it looks like you are arriving and departing Ireland from Dublin. Have you considered renting a car as you leave Dublin for the west coast? Might be easier and most efficient.

We're also staying in Castlemaine and I've used Google view to look at the town. I doubt that is is large enough to have a taxi service.
If you're flying into either Dublin or Shannon you should able to rent a car there.

I realize everything is open in the US on Sunday, but you're visiting a predominantly Catholic country. I would expect very little is open on Sunday.

As a general rule, all car rental agencies in Ireland seem to be closed on Sundays (many on Saturday, too). That's especially true in smaller towns. The exception is rental agencies at airports - they all seem to be open on Sundays, often 24 hours, too. Find an airport somewhere nearby. Kerry Airport (in the town of Farranfore) has a car agency that's open sundays (I know because that's where I was going to drop my car on a sunday morning, until I switched to the airport in Cork instead, since that works better for us to catch a train to Dublin).

You will need to re-arrange/tweak your plans accordingly (as I did when facing the same day-of-the-week limitations).

Insisting on a car with automatic transmission will just turn the difficulty knob up to 11. Consider investing some time to get conformable driving a stick at home before you switch sides of the road. The shifting-gears-with-your-left-hand thing just takes a few minutes to adjust to (just be glad it's not your car as you grind those gears...). By contrast, driving on the opposite side of the road requires constant awareness - be very careful with that. Hopefully you are not driving solo; assuming you have a passenger, it's their job to sit next to you, help navigate, and regularly remind you to stay on the left side of the road (especially challenging immediately after you make a turn onto a new road, it's easy to forget and start driving on the wring side). You co-pilot should offer helpful advice regularly. Be careful.

Where are you coming from before you arrive in Tralee? Get you car the day before, in a bigger town.