Is it too much to do Dublin, London, and Paris in two weeks?

It can be done. You probably won't see everything you want to see. You will spend time traveling between the cities. Depending on the time of year you go, the crowds may make it difficult to pack things in. (If you can avoid travel in the summer it will be easier.)

But three cities in two weeks is not impossible. I wouldn't add a fourth but perhaps a day trip outside of each one.

My only suggestions is to minimize your travel time once in Europe. Some will tell you to take a ferry and a train from Dublin to London. That will take up an entire day. Fly. It's quicker. Between London and Paris stick to the Eurostar. It's faster than flyiing when going city center to city center.

Much easier done if you fly Dublin to compact London City Airport. (LCY) and take the Eurostar from London to Paris..

How many nights will you sleep in Europe? Have you checked air prices flying multi-city? An example is flying into Paris and out of Dublin, etc. If you fly round-trip in and out of Dublin fly to Paris on arrival day and save Dublin for the end of your stay.
Don’t expect to do much sight-seeing on arrival day. Instead, settle in then stay on your feet. Visit museums the next day.
I feel Paris deserves five night, London six nights and Dublin three. If you add day trips add a night per trip.

Use Kayak.com to check and compare flights.

My advice is always to get over the Atlantic Ocean on the best flight for you, whatever that means. I just got back from a two-week (left on Saturday, got home on Saturday, so 12 days on the ground) trip SEA-FRA round trip, train to Amsterdam, Eurostar to London, fly to Cork, train to Dublin, fly back to FRA. The purpose of the trip was a job fair in London. We chose the Frankfurt flight because I could get premium economy at a good price. We lost a lot of time traveling between cities. We chose Amsterdam because it’s on Eurostar and is not Paris (too big for our timeline). I am an experienced traveler. All this is to say that just because you fly into Dublin doesn’t mean you have to visit Ireland. Fly right out again (leaving time for delays, of course). Use Eurostar between London and Paris. You might have to stay the last night at Dublin airport, but lots of people do that on their Ireland trips, too. But check with the family. Maybe they will want to see beautiful Ireland instead.

I don't know when or if we will be back.

Don't sell experience short, spend a little more money.

Assuming 2 days for travel to and from US (unless you planned trip to encompass 3 weekends), you have 12 days on the ground, so 4 days per city. I think that's dooable and I don't think you should fly into Dublin without allowing a little time for Ireland. I suggest you take a day tour from Dublin to Glendalough. Since you should be in Dublin the day before your flight to the US, you should do Dublin last. How are you planning to travel between cities? People say that there are cheap flights between European cities, although I have never done that.

"People say that there are cheap flights between European cities"
There are. I use skyscanner.com to find them. You just have to be very careful about the baggage limits, both dimensions and weight, for personal items, carry-on AND checked bags.

We definitely plan to explore Dublin. Just wasn't sure if we could fit in one, two, or no more cities in that timeframe.

The good airfare was actually a deal mentioned in these forums. 17.5k Alaska Airline miles + $19 each way. Hard to beat that!

We have 11 days to work with total, not counting the days we are doing the big flights. Not sure how to allocate the days for each, but will probably want to do Paris last to time it with my daughter’s birthday. We’d have one day between her birthday and our flight back out of Dublin.

The question is, should fit in another city or two?

No. Two weeks will give you enough of Dublin, London and Paris to make it memorable, but you won't run out of things to see and do. Adding any othe major cities will add to travel time at the cost of seeing the sights. Consider an inexpensive flight back from Paris to Dublin, rather than train to London, then on to Dublin.

Frankly, I would just do two not add more. Otherwise, you’re going to be spending a lot of time “traveling” versus sightseeing.

What do you want your family travel memories to reflect?
You can choose to “see there” and check off a list of cities and sites or “be there” and spend time creating memories of experiencing a few destinations.
Ireland is wonderful offering a blend of experiences in and around Dublin.
London is a huge menu of opportunities offering ez day trips to savor along with time spent in the city.
Slow down, don’t move too fast, you need to create wonderful memories that last.

I think we've decided to skip Paris and focus on Ireland and London area. Doing it this way can also allow us to fly back from London and into one of the western Ireland airports and save a little car time with that. When I go to Paris someday, I'd like to fully savor all of France, so rushing there for just a few days to check seeing things off a list doesn't sound fun, and isn't the way we like to travel. Thank you everyone for your input.

What a great experience for all of you, especially with a killer deal on a flight to Dublin! You said, “It’s hard to not want to see everything.” What “everything” are you thinking … Neolithic sights, Art and/or History Museums, Castles/Chateux, food experiences, pubs, music, nature settings… ?

At this point, you’ve got approx. 4 days per city. Are you possibly more interested in one country than the others, or less interested in one country, where you could reduce the time, giving it to the other destination(s)? As for another city or two, Galway, Ireland (my favorite city there, even more than Dublin, on the western edge of the country, is just 3-4 hours by bus or train, but another 3-4 hours on the return - overall, parts of 2 days. Is renting a car, driving on the left side of the road, fitting in 4 people plus luggage, being considered at all?

Then there’s Ennis, which has a big Irish music festival in May/June. It’s not far from the Shannon airport, so even if you’re flying home from Dublin, you could fly in to Dublin, fly from Shannon to London or Paris, take the Eurostar to Paris or London, then fly back to Dublin before heading home. Shannon could give you an option for another city for a quick second place in Ireland. Other towns are worth visiting, too, but take a while to reach. Great daytrips from Dublin, while still lodging in Dublin, include the Newgrange Neolithic sights. We stayed in Trim, closer to Newgrange, and with its own castle, but we had a car. Belfast, Northern Ireland, would give you yet another experience, but you’d need to get there, although that gives you yet another airport for reaching London or Paris.

London - there’s York, reachable by train as a potential additional city option. London has so many day trip options - Bath, Oxford, Cambridge, Windsor, etc., plus full-day side trips at the edge of London, like Greenwich and Hampton Court.

Paris - the TGV bullet trains can whisk you to potential second city options, like Amboise in the Loire Valley, or south to Avignon or Arles for Provence. There’s also Normandy and D-Day beaches. Closer Paris day trip options would include Versailles.

Cut a day here and add it there. You could squeeze in another location or two, but of course that would be at the expense of time staying in your current Big Three Dublin/London/Paris locations, inside those cities themselves. Maybe tough decisions to make, but if going back again is in question, then any places you pick will be worthwhile. You just have to figure out how to get from each place to the next, and how long (and how much money) that will take.

With limited time, we try to have a short list from each person in the family of what they most want to see in/near our destinations. Often they are not the top of must-see tourist spot lists, but they are important to one of us. For instance, in all of Paris the two things our kids wanted to see most were the catacombs and Normandy. Yep, Normandy isn't in Paris but we did take a day trip (fast, not normally recommended) to see the D-Day sights. Best two days of the trip were the catacombs and Normandy, hands down. We skipped 100% of the museums because they don't interest us as much. No regrets. What are the things your family is most interested in exploring? We loved the less visited sights in Ireland but we're not city people. And for a lot of them you might need a car. Are you comfortable driving there? Dublin has a number of amazing day trip options, either on your own if you're comfortable driving or with a tour or public transportation. Same for London.

We rarely get to travel to Europe but each time have flown into Dublin or London because the flights have been way less expensive. And we've traveled on to our intended destination using the budget European airlines (be careful to read the baggage rules as previously mentioned!). Pricing has always worked out better for us to return from the same airport... so back to London or Dublin for the flight home. So far, that option is what has enabled us to afford the trips. We've flown London to Dublin... easy and quick.

We just returned from a week in Ireland. Rented a car so we could get to our personal top wish list of sights. Don't be afraid to venture away from the "top ten" lists that everyone wants to see, depending on what appeals most to your group. We tend to avoid cities but I think that's not really as common. And definitely can require a bit of extra planning.

There are a lot of travel styles and with limited time, it seems to come down to what you think will work best for your family.... the lingering deep dive into one or two places or a potentially exhausting whirlwind tour getting to a number of places you never thought you'd get to see in person. There are compelling arguments for both. Our family tends to favor the second option. We cram in a lot, choose just the things that really interest us, and rarely spend more than 1-2 nights in a single location. We drove way more than usually recommended in Ireland and had an absolute blast. I can definitely see why this would not appeal to a lot of people, but it works for us. We have never regretted our choice to move fast. And we loved our extremely quick side trip to Gibraltar and southern Spain enough that we're dreaming of returning some day for a longer, more focused visit. Enjoy your planning!

If you only go to these three places, this is doable. How you divide the time? It depends on your interests. It is easy to spend a week in London or Paris..... I love Ireland for a fun visit bit I would limit the time there to allow more time in London and Paris. Which of those gets more time depends on what you want to do. This would be a visit that should be well researched in advance.

These 3 places are easy to see in 2 weeks. We did a similar trip with 2 weeks, but instead of Dublin we had Edinburgh. I would not try to add any other cities as I think you will find this is a lot to see without rushing too much.