The hotel is lovely and only a short walk to Grafton Street and Temple Bar. The hotel has an older, more European feel straight with radiator wall heaters and everything. But the bathrooms have been newly remodeled and every room has digital TV. The beds are super cozy too. The breakfast in the morning is pretty good. The front desk was extremely helpful with all my questions and needs. Would definitely stay there again!

This is a reasonable hotel for the price. Very friendly reception staff (Nikola was particularly helpful). Check in very efficient, the whole hotel is fairly dated, including the rooms, but for the price all very clean and perfectly acceptable.
Would recommend and return.

I have just returned from six nights at the O'Callaghan Mont Clare and would recommend it with no hesitation.
I chose it primarily based on location and price (having shopped around on the internet and manage to snare it for under £50 a night) as it is just around the corner from Trinity College, and was pleasantly surprised with a high level of service and luxury despite the 3-star moniker.
The rooms are large, clean and quiet. I was in room 350 (on the third floor at the front of the building), which was enormous and sufficiently soundproofed to sleep through the Dublin rush hour.
I would definitely stay again, even at a higher price level. You would be hard pressed to find a better economy level option in central Dublin.

We stayed as a couple for a total of 5 nights. Our first 4 nights were spent in room 426. It was at the back of the building away from the street and very quiet. Our last night in Dublin we stayed in room 410 which faces the street. It was a Sunday night so we thought it would be quiet but there is certainly street noise on that side of the hotel. Lots of traffic starting early morning and of course some drunken idiots yelling at 2am.
Overall we were pleased with the staff and our stay. We would just recommend asking for a room away from the street if possible.