Best Debit Card to use in Ireland?

Either VISA or MasterCard networks (Cirrus, Plus) debit cards will for fine regardless of who owns the card. Check with your bank to determine to see if BA has an reciprocal agreement with any Irish bank that could min fees. But you can use your BA debit card at any bank ATM.

Bank of America isn't even in all 50 states, why would it be in Ireland? Check with BA to see what their transaction fee is.

"what card is the best to use to avoid fees?"

Charles Schwab, TD Bank, and credit unions are frequently mentioned here as places to get debit cards that have lower foreign transaction feels for use at overseas ATM's.

For instance, if you use your BoA debit card at an Irish bank's ATM, you'll pay 3% plus $5 per withdrawal. With a basic TD checking account ($100 minimum), you'll pay just $3 per withdrawal (no extra %age). And with a fancier account ($2500 minimum), you'll pay $0 per withdrawal.

Whether you want to set up a new account just for travel is a different question.

Note that even a high fee ATM card like BoA's is still cheaper than buying euros in the US or changing cash in Ireland.

You might be able to find a BofA affiliated bank ATM in Ireland to save their fees, but that could take a lot of time away from your enjoying your trip.

Capital One 360 Bank has a MasterCard debit card with zero fees anywhere at any bank. And I really mean ZERO. I have used them for all of my trips to Europe and never have been charged a cent in fees nor have I ever had issues with transactions not working. The exchange rate also matches to the penny the rate you see on Google, so no markup there either. I would suggest this card is only used to get cash out of ATMs and you use a no-fee credit card for any non-cash purchases.

IF you have time before your trip, you can open an account with them with no minimum amount needed or minimum monthly balance requirements. It is all done online. They allow transfers in to the account for free if initiated from their end to fund your travels. Their app works amazing well too and you can do all your banking (like moving money around) from there.

Bank of America cards have some of the highest fees around. Typically $5 per use and then 3% of the transaction in "currency conversion fees" By finding an affiliated bank, you will save the $5, but not the 3%. As others have said, look for a Credit Union or just set up a Charles Schwab Account. I have used a Schwab account on two trips now, no issues, few weeks to set up, I use the account to build a travel fund.

I just checked and found this BofA info about affiliated banks https://locators.bankofamerica.com/international.html
but there is no longer a partner in the Irish Republic. And, like Mark and Paul and others said, it is not as great a thing as it was in the past. There are still some fees, even with the partner banks.
I'm sad about this.

But I do have a Capitol One MasterCard debit card that I never use, and I suspect (and hope) it's the one Mark mentioned! I usually keep only $100 in that account, but I've just transferred in some money, for Ireland use anyway.

We,too, have used the Capital One Debit Card all over the world without incurring fees and they also refund back the ATM fees from the other banks. We only use this card for debit transactions.

Thanks to all of you who recommended the Capital One debit card.

I've never used it before but I transferred money into that account and am looking forward to getting cash without fees.

Their website says that their App will help us find participating ATMs.

The Capital One 360 App helps you find ATMs in the US that do not charge a fee -- not too helpful in Europe. But since nearly every ATM in most of Europe doesn't charge fees, you don't really need the help of the app. :-)