There is a farmers market in Cahir on Saturday mornings, beside the Craft Granary on Church Street. Small, and genuinely local rather than a craft market with a vegetable stall at one end.
What makes it worth the trip
Everything on the stalls except the fish is produced within twenty miles of Cahir. Not a slogan on a banner, an actual condition of having a stall.
So the stalls do not duplicate each other. Two vegetable growers, two fruit growers, a fish stall, a juice producer, three home bakery stalls doing bread and confectionery, a butcher specialising in traditionally cured pork, and a certified organic farmer selling beef, lamb and farm produce. Organic wine and chocolate as well.
For a town of this size that is a serious market.
Go early
The single practical thing to know is that most stalls sell out inside the first couple of hours. The baking and the seasonal fruit go first. If you arrive towards the end of the morning you will still have a pleasant time and you will not get the bread.
Where it is
Church Street, beside the Craft Granary, a couple of minutes' walk from the Square and from Cahir Castle. Park once and do the market, the castle and the riverside walk in the same trip.
Check the market's own site before travelling, particularly around bank holidays, since a street market is exactly the sort of thing that moves or skips a week.
If you are self catering
The market is the obvious answer to the first shop of the week. Better than the supermarket for produce and meat, no use at all for everything else, so do both. Shopping in Cahir covers the rest, and self catering in Cahir covers the accommodation it suits.
The rest of the food
If you are eating out rather than cooking, the best places to eat in Cahir and cafes in Cahir are the lists. Several of the town's kitchens buy from the same producers you will see on the stalls.