Enough takeaways to cover a night in, split between the town centre and the service station out on the Mitchelstown road. Which end you use comes down to whether you are walking or driving.
Chipper
Chipmongers at O'Donnell's, Woodview Service Station on the Mitchelstown road is the fish and chips in Cahir. It is part of a national chain rather than an old family chipper, which in practice means it is consistent and it is open when you need it. The service station location makes collection easy if you are in the car, and awkward if you are not.
Pizza
Pizzeria Restaurant and Takeaway on Abbey Street is the local one. It has a small dining room as well as the takeaway counter, so you can eat in if you would rather not carry it home.
Eskimo Pizza covers the chain delivery end and is on Just Eat, which is the easiest way to see whether it is taking orders tonight.
Chinese and Thai
Dream Garden on Old Church Street is the main one, a sit down Chinese restaurant that also runs a Thai menu and does a large collection and delivery trade. It is the most reliable evening option in the town once the restaurant kitchens have closed their books.
Foo Lum and Yummy House are the other Chinese takeaways in Cahir, both collection led.
Italian, to take away
Galileo in the Mill Building on Church Street is a sit down Italian restaurant that also does takeaway, so it is an option if you want something better than a chain pizza without eating out. It is covered in more detail on the best places to eat in Cahir.
Delivery
Cahir is small enough that a good part of the trade is collection, and some places that will feed you will not bring it to you. Just Eat shows which Cahir outlets are delivering at any given moment, which is more current than any list here can be: takeaways change names and platforms drop them without warning. If you are staying outside the town, check the delivery radius before you build the evening around it.
The rest of the eating
For a sit down meal rather than a bag, evening meals in Cahir covers dinner, pubs in Cahir covers bar food and a pint, and cafes in Cahir covers the daytime.