Interior decor of Irish pubs range from the simplicity of the small country pub at one end of the spectrum, to the sumptuous Edwardian interiors of the finest Dublin and Belfast pubs at the other, but certain items and motifs tend to be common to all. Antiques, unusual Irish artefacts, curiosities, old Irish advertising, enamel signs and pub mirrors are usually found in most Irish pubs and are generally an imposing piece of art in their own right.

The counters of pub bars are usually made of mahogany, and hold taps through which draught beers are poured. Draught ales and stout are a comparatively recent innovation in Irish pubs, and in most of them beer flows through little illuminated attachments provided by suppliers to advertise their beverages. But some older pubs still possess the earlier wooden pumps with brass attachments and these, when they are polished and shined, can be particularly attractive.

The pub clock, usually kept a few minutes fast to encourage customers to leave at closing time, takes a number of guises, the most typical perhaps being the round faced mahogany version. Some older pubs have American pendulum clocks, so called because they were sent back by emigrants to the United States as presents. These clocks are recognisable by the maker's name inscribed in them, which usually identifies the American city where they were manufactured.

The area behind the counter, the 'bar', has had its name extended to offer an alternative term for the pub itself. The bar is the most brightly lit part of the premises, contrasting with the dim recess where customers huddle over tables in deep and private conversations.

In many older pubs gas lamps preceded the electric light, a few establishments still possess their original brass lamps, now converted for electric bulbs. The Art Nouveau stained glass Tiffany style light shades in some pubs are invariably recent introductions, though of the appropriate period they were mostly uncommon in genuine Irish pubs of the Edwardian era.

The influence of Guinness, with its distinctive advertising, is felt both inside and out. Probably all Irish pubs, old and new, have Guinness signs on display in a variety of forms. The various advertising campaigns carried out by Guinness over the last century have had a strong effect on the 'look' of the Irish pub. Very commonly seen is the most famous of all Guinness slogans, 'GUINNESS IS GOOD FOR YOU', which dates back to 1929 and has passed into the English language as a catchphrase.