$338 Find Cheap Flights from Ireland to Illinois

1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Illinois

 
These are the airlines KAYAK users have selected most often from within our search results for flights to Illinois, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results for flights to Illinois, as well as popular online travel agencies
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Booking Insights

KAYAK's insights & trends for flights to Illinois

Get data-powered insights and trends for flights to Illinois to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest flight to Illinois?

These are the best round-trip prices found by users searching on KAYAK in the last 72 hours.

The cheapest ticket to Illinois from Ireland found in the last 72 hours was to Chicago O'Hare Intl Airport, at $397 round-trip. The most popular route is Dublin (DUB) to Chicago O'Hare Intl Airport (ORD) and the cheapest round-trip airline ticket found on this route in the last 72 hours was $397.

What is the cheapest month to fly from Ireland to Illinois?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights from Ireland to Illinois, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ireland to Illinois is November, when tickets cost $476 (return) on average. On the other hand, the most expensive months are July and August, when the average cost of round-trip tickets is $785 and $730 respectively.

How far in advance should I book a flight from Ireland to Illinois?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights to Illinois, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ireland to Illinois, you should book around 3 weeks before departure, which saves you about 29% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 15 weeks before departure.

Which is the cheapest airport to fly into in Illinois?

Prices will differ depending on the departure airport, but generally, the cheapest airport to fly to in Illinois is Chicago O'Hare Intl Airport (ORD), with an average flight price of $609.

Good to know

Low seasonJanuary
Cheapest flight$338
Best time to beat the crowds but there is an average 13% increase in price.
Most popular time to fly with an average 2% increase in price.
Flight from Dublin to St. Louis

FAQs for booking flights from Ireland to Illinois

  • How does KAYAK find such low prices on flights from Ireland to Illinois?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ireland to Illinois.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ireland to Illinois?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Ireland to Illinois is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ireland to Illinois?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from Ireland to Illinois with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ireland to Illinois?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from Ireland to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest day to fly to Illinois?

    Based on KAYAK data, the cheapest day to fly to Illinois is Sunday where round-trip tickets can be as cheap as $680. On the other hand, the most expensive day to fly is Thursday, where round-trip prices are $839 on average.

  • What is the cheapest time of day to fly to Illinois?

    The cheapest time of day to fly to Illinois is generally in the morning, when round-trip flights cost $766 on average. Morning departures are around 1% cheaper than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $827.

Reviews of the top 3 airlines serving from Ireland to Illinois

 
See real verified KAYAK customer reviews for airlines flying to Illinois. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline from Ireland to Illinois. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Ireland to Illinois? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 9198 reviews
7.7Boarding
6.6Food
7.3Comfort
8.1Crew
7.1Entertainment
Airline reviews

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

4.0 OkayStephen, Jan 2026
SMF - ORD
Read more United Airlines reviews

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

I so appreciate the crew members on each flight of United. They are outstanding.

Reliable, nice crew, I fly often on that flight and I like it all.

Perfect flight. Smooth flight. Arrived 20 minutes early at destination. Excellent service.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

Everything was absolutely wonderful from check in to baggage claim. Staff was very professional and sweet. Will definitely recommend United to family and friends.

The staff was nice, however boarding taking 2 hours. That’s insane. Overall very bad experience, a lot of turbulence and when landed in Chicago was horrible. I don’t think I’ll flight with UA again.

An international flight on an apron is pretty unusual in my 40 years of traveling. Departure delay. Luggage despite over an hour connection did not make it to the flight. Actually still in Germany. My luggage was not moved until I reached my final destination despite knowing it to be left in Germany upon my arrival in Chicago. The service left me a little off, both going and returning from Europe. Light on in the cabin even during a night flight and lots of traffic no matter what. Maybe passengers want more service? As a frequent traveler i just want to be able to sleep, the food will be better at the destination anyway. So since the cabin crew woke me up I asked for a cocktail, I did not get the best response although sitting in row 20 premium economy. I usually fly premium economy or business and my 2 flight to Europe in 2025 with United both had luggage delays and other minor issues. American flights to Australia, Canada and Europe went smoothly and Premium plus feels very much like business light. Is United Club becoming a waste and Silver/Gold levels another waste??

They did the one thing that really matters - got to Chicago early.

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

One of the best flight experiences I've have had in along time. Would fly with them again.

So, the trip from Dublin to LA did not really happen because the flight took off before we could finish the transfer.

Very nice experience. Flight had good entertainment system and good food options. Customer service was very friendly and nice as well.

Like - the crew were nice Dislike - sitting on the tarmac for long periods after boarding and landing.

I was not admitted to the flight!!! i need a refund for this.

It’s my new favourite airline! Everything was smooth and relaxed!

One of the best flights I've been on in a while. Very genuinely friendly staff. Courteous, kind, respectful. On a past flight (not Aer Lingus) I remember being woken up rudely to put my seat forward. Like a child being berated for something. Oddly jarring experience when someone could just tap you gently on the shoulder and gesture kindly. But I noticed the Aer Lingus staff were incredibly patient with everyone on the plane. It's the holiday season and I noticed a lot more elderly customers on the plane than I typically see flying, and the staff went above and beyond with helping accommodate people. Service throughout the flight was flawless. They came through offering water, and picking up garbage at perfect intervals. Seemed like this flight, everyone was on point. And the flight landed early on top of that

Seats are small, but comfortable and more space around you, so for a normal person the seats are perfect. If you are a big and fat individual, I would not think the seats are comfortable. All else was good and normal. Lots of movies to watch.

Customer service was excellent! The app was terrible, tried several times to check in without success! But the young lady that checked us in was absolutely terrific and helpful.

The same as I stated prior. We incurred extra costs that should be reimbursed, given we were not communicated with about schedule changes.

We were in premium economy seats that appeared to be locked in plae, No reclining. My aching back.

I don’t understand how they charge as much as they do for such a poor experience

I wish the plane had pod seating for business class. I had a window seat (8K) and I had to climb over the person sitting on the aisle when I needed to get up. Also there is no partition between the seats for privacy when sleeping. The Asian airlines have much nicer business class seating. Their seats are wider for better comfort when sleeping.

The seat space seemed small especially when the person ahead reclined but other than that, very good.

Luggage transfer in Chicago was not performed in time. I received my luggage at my destination two days later.

Food was poor quality and the screens for entertainment didn’t work properly

It was a short flight, everything was good with it.

I darted through the Frankfurt airport to make my connecting flight. I asked if it was a possibility to upgrade and the agent did. This was the kindest gesture and it made up for the previous delayed flight and distress/anxiety of anticipating that Zi was going to miss my Frankfurt-Chicago connection. I cannot express my gratitude for the upgrade.. I am 5feet 10 inches do the leg space was amazing.

I meant this flight was not good, the one from Tirana to Frankfurt was better!

I was very grateful for Lufthansa's role in organizing mobility support. The touchscreen on my seat was faulty: slow, stained (I couldn't get it clean), and glitchy. This made selecting movies extremely time consuming, and twice I had to start all over from the beginning.

Everything you need to know for your flight to Illinois

Cabin class types available on flights to Illinois

Cabin classes available on flights to Illinois. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.