Scotland/Ireland in 10 days

"I want to see the USA and Canada this summer. We have 10 days."

First step: Recognize this is not a wise choice. Sorry to be blunt, but it's not. You simply can not see much of either place if all you have is 10 days for BOTH together.

Pick one or the other, not both. Both Scotland and Ireland are wonderful, and either one deserve a couple weeks as a bare minimum. Choose the one that calls to you most, and then come back and work on that one (and how to try to squeeze it into just 10 days).

Ten days isn't much time for both countries. You might consider just one or the other. You might also want to look at Rabbies Tours for both countries. I haven't taken one but they have a good reputation in this forum and elsewhere.

I'd recommend flying "open jaw," that is a multi-city itinerary where you land in one country and depart from the other. That will save you time by not backtracking, and the cost should be comparable to a round-trip fare to just one city. Given your time constraint, you should probably also fly between Scotland and Ireland.

Here are some ideas: Fly into Dublin. See Kilmainham Gaol.Trinity College/Book of Kells, Traditional Irish Music e.g. pub-- The Cobblestone, Glasnevin cemetery, New grange, goto Belfast, city walk, giant’s causeway, fly to Edinburgh, royal mile, Edinburgh castle, day trip to fly home from there or Glasgow

Lots of other stuff to see but if you must see both and have 10 days then maybe 3 in Dublin, 2 in Belfast, Edinburgh/scotland for the rest-- rent a car and see as much of highlands as you like in your limited time.

Good luck!

Great tour company in Ireland is Stephen McPhilemy's Essential Ireland. He's a Rick Steves guide with his own company.

"I want to see the USA and Canada this summer. We have 10 days."

That's good!

Some people can be snarky. Scotland and Ireland aren't anywhere near as big as the U.S.A. and Canada. Not everyone can take multiple trips to Europe. It can be good to at least see a little of some countries versus none at all.
We are doing a 12 day trip to Scotland and Ireland this year. You just need to spend a little time planning. Here are some ideas: fly into Edinburgh and stay there 2 nights. Pick out your favorite museums or historical sights. Then stay 2 nights in Glencoe. There are many rental houses within 20 miles of Glencoe on airbnb. This can be a home base for seeing some of the mountains and lochs. Stay a 5th night somewhere near a place you want to visit. If you prefer the city and shopping and restaurants, then just go back to Edinburgh or Galway your last night in Scotland. Some highlights are: Sterliing Castle, Edinburgh Castle and Eilean Donan Castle, the Glenfinnan Viaduct and train, National Museum of Scotland and Scottish National Gallery. Visit the website visitscotland.com for ideas. The website has a lot of info. You may be able to take in highland games or some other event. The sun sets after 10 pm in June.

Fly on Aer LIngus or Ryanair to Dublin, Cork or Shannon and stay there 1 or 2 nights. Travel to Limerick or Killarney or Kenmare and see the Dingle Peninsula or Ring of Kerry or see the Cliffs of Moher or Kerry Cliffs. Fly home from Shannon or Dublin. Returning the rental car to the original location is cheaper though.
Just realize you will be running the whole time and will go home exhausted. It is worth it to us. I have a ton of memories and photos and I can rest when I get home. When we first land in Europe early in the morning, we do a 4-5 hour day sightseeing then get a quick late afternoon supper and go to bed really early and rest 10-12 hours to catch up on jetlag and the time change, otherwise you just stay tired for days.
Spend time researching travel sites and youtube videos and make a wishlist of your favorite places in each country. Make notes or a Word doc etc and start sketching out your itinerary. Double check events for your area before you nail down your days. Have a big city base, then a smaller scenic town base for each country. Then start filling in your lodging near those areas. Pack light because running around is a lot harder with several heavy suitcases. Having snacks in your car gives you more time for sightseeing and less time waiting at a restaurant.

I think you can manage this if you want to see two countries. Fly into Edinburgh and spend five.days and fly into Shannon which will put you on the west coast of Ireland near Dingle. And the beautiful.scenery. Rent car.at Shannon and then set off, returning the car to Shannon and home.from there. You will be flying open jaw not two one way to tickets. Be aware when returning to US you need three hours at airport to.clear.US customs arriving in US as if on .domestic flight. That is why I would go.to Scotland first and home.from.Ireland. also.be aware with the low.cost.airlines between those two countries they are very strict with their rules such as pre- printing boarding passes, size of carry-on.etc. enjoy.

Personally, I would not attempt this as it takes a lot longer to get around both countries than you may think. As North Americans, we look at the size of these countries and the distances from place to place and think that’s not far, but it is deceiving. I spent three weeks in each country, and still felt I had only scratched the surface. However, if you only have ten days, and you really want to see both, then you could get a taste of each country, but you will have to really narrow your focus. I spent 6 days in Edinburgh, and managed to see a fair bit making use of guided day trips to get to many places. I also did this in Ireland using larger towns as a base to take guided day trips from. So, if you were to pick two locations, one in Scotland, and one in Ireland, to base yourself in for a few days then use guided day trips to see the sights you could manage to see a fair bit without having to rent a car. You would fly into one city, and home from the other, and then you would only have to figure out how to get from Scotland to Ireland.

Yes, you clear US customs in Ireland before flying back to the US, so you will probably need a full 3 hours at the airport. You do not clear US customs in Scotland or England but they still advise 3 hours before international flights. And I think people on here are just trying to offer advice that your trip may be more enjoyable if you don’t try to do too many places within your ten day timeline, but that’s up to you.