Enjoy Breakfast and Bottomless Brunch at O'Neill's St Mary Street, an Irish-themed pub specialising in Irish music, food, and drinks. Experience a warm and friendly atmosphere while enjoying their range of great Irish beers, including their exclusive Smithwick's Red Ale.

Breakfast at O'Neill's is chocked full of traditional Irish dishes and ingredients, with their Irish pork and leek sausages taking centre stage on most menu items. Enjoy three different sizes of Traditional Irish breakfast, each with fresh, free-range ingredients from Ireland. Fancy something a little smaller? No problem. O'Neill's also offer their "No-Brainer Breakfast Baps", featuring hearty Irish Breakfast sandwiches, as well as their range of Breakfast oats and porridge.

Bottomless Brunch, or Bottomless Lunch as O'Neill's call it, is a unique yet delicious experience at the Irish Pub chain. Diners will be given a range of drinks to choose from, accompanied by a pizza of their choice.

O'Neill's St Mary Street is located right in the centre of Cardiff, just beside the Principality Stadium, and a two minute walk from Cardiff Central. 

Expand Description

Bottomless Brunch:

Thursday-Sunday: 12PM-3:30PM

  • Bottomless Drinks
  • Breakfast
  • Brunch
  • Groups
  • Private Dining
  • Vegan options
  • Accepts Credit Cards
  • Disabled Access
  • Online Booking
85-87 St Mary Street, Cardiff, CF10 1DW
Overall rating
4.3
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  • 4.0
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    2 months ago
    nice food, was quiet when we went there which is unusual is lovely supervisor shame about the first guy that served us didn’t get his name, looked very unhappy in his job! work in customer service myself so know how first hand impressions count 😊 thanks lewis, for rectifying poor service!
  • 5.0
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    2 months ago
    O'Neill's: The pub where the Guinness flows as smoothly as the banter, and the hearty portions of food could probably feed a small village—assuming that village isn't too picky. From the moment you step in, it feels like you're either in an Irish village or a cozy, slightly chaotic living room of a long-lost friend. The staff are like family, if family was full of people who didn’t mind cracking a joke or two while serving you. And let’s talk about the food: If your stomach had a voice, it would be singing praises after a plate of their fish and chips. Crispy, golden, and practically begging for you to dip it in tartar sauce—this is comfort food at its finest. The drinks? Well, it’s O’Neill’s, so expect a pint of Guinness so perfectly poured, you might start wondering if the bartender is actually a wizard. The ambiance is a delightful mix of cozy and lively—like someone threw a traditional pub into a blender with a splash of good vibes. The only downside? You might leave with a food coma and a lighter wallet, but hey, that’s the price you pay for a night of laughter, food, and pints that come with a side of Irish charm. Would I recommend it? Absolutely—just make sure you’re hungry, thirsty, and prepared to leave with a smile on your face (and a bit of a food baby).
  • 5.0
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    2 weeks ago
    Quite good English breakfast for a reasonable price. You will always get a seat in the morning for it. Might get busier in the evenings.