$816 Find Cheap Flights from Sydney to Illinois – Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Sydney to Illinois departing on 25/7. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
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 in flight searches from Sydney to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Sydney to Illinois.
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Flight Deals

Book Cheap Sydney to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for return flights from Sydney to Illinois that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent return flight deals from Sydney to Illinois

Mon, 13 Jul - Wed, 12 Aug
Multiple Airlines Logo
13:15 - 06:17
SYD
-
ORD
32h 02m
2 stops
Multiple Airlines Logo
07:15 - 22:10
ORD
-
SYD
47h 55m
3 stops
$1,390Multiple Airlines
Fri, 28 Aug - Mon, 7 Sep
American Airlines Logo
09:10 - 17:37
SYD
-
STL
47h 27m
2 stops
American Airlines Logo
05:42 - 06:55
STL
-
SYD
34h 13m
1 stop
$1,391American Airlines
Wed, 26 Aug - Tue, 8 Sep
American Airlines Logo
09:10 - 22:59
SYD
-
STL
28h 49m
1 stop
American Airlines Logo
06:36 - 07:05
STL
-
SYD
33h 29m
2 stops
$1,414American Airlines
Wed, 26 Aug - Mon, 7 Sep
United Airlines Logo
10:20 - 18:39
SYD
-
STL
23h 19m
1 stop
United Airlines Logo
12:59 - 07:00
STL
-
SYD
27h 01m
2 stops
$1,440United Airlines
Wed, 26 Aug - Wed, 9 Sep
Qantas Airways Logo
09:10 - 22:59
SYD
-
STL
28h 49m
1 stop
Qantas Airways Logo
06:30 - 07:05
STL
-
SYD
33h 35m
1 stop
$1,479Qantas Airways
Sat, 29 Aug - Sun, 6 Sep
Qantas Airways Logo
17:50 - 22:59
SYD
-
STL
20h 09m
1 stop
Qantas Airways Logo
18:45 - 06:55
STL
-
SYD
21h 10m
1 stop
$1,480Qantas Airways
Sun, 15 Nov - Sun, 22 Nov
Delta Logo
10:40 - 17:21
SYD
-
ORD
23h 41m
1 stop
Delta Logo
14:55 - 08:30
ORD
-
SYD
24h 35m
1 stop
$1,513Delta
Sun, 13 Sep - Tue, 13 Oct
Delta Logo
09:15 - 21:58
SYD
-
ORD
27h 43m
2 stops
Delta Logo
08:55 - 07:50
ORD
-
SYD
30h 55m
2 stops
$1,525Delta
Thu, 19 Nov - Wed, 6 Jan
Air New Zealand Logo
09:55 - 22:36
SYD
-
ORD
29h 41m
2 stops
Air New Zealand Logo
14:10 - 08:45
ORD
-
SYD
25h 35m
2 stops
$1,702Air New Zealand
Wed, 9 Sep - Mon, 14 Sep
Air New Zealand Logo
09:55 - 23:05
SYD
-
ORD
28h 10m
2 stops
Air New Zealand Logo
15:48 - 10:40
ORD
-
SYD
27h 52m
2 stops
$1,706Air New Zealand
Booking Insights

KAYAK's insights & trends for Sydney to Illinois flights

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

How much is a return flight from Sydney to Illinois?

This analysis is based on the cheapest return trip price found on KAYAK in the last 12 months by searching for a flight from Sydney to Illinois departing in July.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Sydney 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 Sydney to Illinois is December, when tickets cost $662 (return) on average. On the other hand, the most expensive months are July and February, when the average cost of return tickets is $1,302 and $1,224 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Sydney 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 a flight from Sydney to Illinois, you should book around 2 weeks before departure, which saves you about 33% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 20 weeks before departure.

Good to know

Low seasonMarch
Cheapest flight$816
Best time to beat the crowds (3% less expensive on average)
Most popular time to fly (8% more expensive on average)
Flight from Sydney to Chicago O'Hare Airport

FAQs - booking Illinois flights

  • How does KAYAK find such low prices on flights from Sydney 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 Sydney to Illinois.

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

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

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

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional return ticket. You could then fly from Sydney 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 Sydney 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 Sydney to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines flying from Sydney to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Sydney to Illinois. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. 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 Sydney 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.
8.3
ANAOverall score based on 1236 reviews
8.2Comfort
7.7Food
8.5Boarding
8.7Crew
7.9Entertainment
Airline reviews

Although the crew was eventually very good, they complained loudly about EVERYTHING before the takeoff. Did not set the stage for a good trip in business class. The western meal choices were pretty mediocre as were the wine choices. We took an ANA flight to Tokyo and they were outstanding!

10.0 ExcellentAnonymous, June 2026
NRT - IAH
Read more ANA reviews

Although the crew was eventually very good, they complained loudly about EVERYTHING before the takeoff. Did not set the stage for a good trip in business class. The western meal choices were pretty mediocre as were the wine choices. We took an ANA flight to Tokyo and they were outstanding!

As usual the flight from AUS in Austin to SFO was late because they didn’t have adequate staffing to board the plane on time creating a 1 hour delay, which resulted in me missing my flight to Osaka due to a missed connection. When I got to the gate 10 minutes late after landing exactly the time the connecting flight was taking off, I saw my flight to Osaka sitting at the gate and that gates had closed. I attempted to contact United Via chat on the United App and was given the runaround and passed between 2 separate “agents” who after saying they could rebook me, told me I needed to go to ANA even though they’re partners and all of my ticketing was through United. After going to ANA’s gate at SFO to try and get help I was told I would need to leave and go to United’s ticket counter in order to get help. The ANA agents said that it was United’s issue. An hour after running to try to make my flight I got to the United counter. I showed the agent my itinerary and she helped as much as she could. I was booked on a flight that would occur 13 hours after my original flight to Osaka and given $45 in vouchers which doesn’t cover much at SFO. I had also spent 30000 miles with United to get an upgrade with more legroom. And that was not refunded to this point. Ultimately I lost 1 whole day of vacation in with my wife and kids and, the 30000 airline miles and I’m out the money and time I spent. In these situations United and their partners should go out of their way to communicate and accommodate but I was left to my own devices to find the right resources. The only option was to fly to Seoul 12 hours and take a connecting flight to Osaka: I am a United Skyniles member and would not recommend booking a flight with them unless you thoroughly understand the routes as it is likely you will be left to your own devices to resolve the situation.

Staff at gate and crew on plane efficient and friendly.

I liked the flight over all. Towards the middle of the flight. There was a flight attendant who felt like they were rushing to had out vegetarian wraps and said they were “sandwiches”. She also handed out hand we wanted the water but she was walked so fast we didn’t get any. We sat in the seat 45 E & D. And towards the last 30 minutes of the flight there was an announcement saying the crew would collect trash. No one ever came around. So held on to the trash until we landed and left in the seats.!

As always, there is that one or two flight attendants that could be better.

I loved everything about my experience!!! The staff were absolutely incredible. I can not wait to fly again with them.

ANA split my family of 4 by seating us each separately which didn't seem to make much sense. Both ways we were not seated together and the glitch int he online check in system meant we could not change our seats or get boarding passes without seeing a person at the airport counnter. The staff however offered good service in the air.

The seats were broken for several of us on this flight not to mention dirty. Quite unacceptable for the price point and expectation level. The meat was so hard it could hardly be cut so terribly unappealing. The united lungs in SFO was dirty and the bathroom conditions were down right disgusting. Nothing about this experience makes me want to book with United again. Our experiences with business class on Lufthansa and British Airways far out perform United in comparison. Truly disappointing!

It was good. The crew was efficient, food was good

They did not get back tickets in time about flight varification so i had to purchase another one way ticket to get home soxas rocnot Risk being unable to return home.

We got to experience Premium Economy from Sydney to Auckland and it was a great experience wiht Air New Zealand. The crew was friendly and helpful.

Great first time experience with ANZ. Such a great customer service. The crew was very friendly and welcoming

Great airline service by the staff. I highly recommend it

Time to upgrade those planes so you can provide first class.

My experience with Underpricer was not great. The representative assigned to me did not tell me beforehand that selecting seats, which i could not do through ANZ, WOULD ADD SIGNIFICANT cost to my ticket (all flight segments were reg economy seats. The seat selections for the ticket, MCI-AKL, AKL-PER, PER-MCI, cost $284 USD. I WAS NOT TOLD AHEAD OF SELECTING SEATS chosen by the rep OF THE COSTS and never received an itemized invoice of the seat selections.). The costs of seat selection, an option solicited as a service, with no mention of costs, should have been disclosed to me prior to seat selection and certaily should have been itemized. For all I know, the $284 was not referred from the airline but made up and taken directly by Underpricer. Next, when i checked in, united couldnt find my ticket. This is probably why i didnt get a seat selection on that flight and couldnt check in online, despite Underpricer prompts to do so a week before departure, or at the kiosk at the airport. I had to wait for special help at the counter, then was told that because the flight segment, MCI-IAH, operated by United Airlines via the ANZ. ticket, had changed schedule slightly since I BOOKED MY FLIGHT, the MCI-IAH segment had been decoupled from the rest of the ticket because the IAH layover was now 12.5 hrs AND DID NOT QUALIFY AS A THROUGH FLIGHT TO AKL.. This meant my checked bag could not be checked through to AKL and id have to pick it up at IAH, THEN WAIT MOST OF the long layover WITH the large checked bag until ANZ counter in IAH OPENED for checkING just prior to the flight. Apparently, although underpricer had notified me of schedule changes, they did not update the ANZ TICKET, leading to this problem. Finallly, although I RECHECKED TH BAG IN At IAH 3.5-4 hours before the scheduled departure and the IAH-AKL segment was a direct flight, ANZ LOST MY bag and it took 4 days to find it and get it to me. Not fun.

The flight was smooth and on time. Entertainment options were lacking and there was no food, other than some very boring snacks.

A better selection of entertainment would have been nice. I found nothing that appealed to me as a middle-aged traveler. The flight attendants were gracious, helpful, and attentive. It also would have been nice to have more bathrooms as the flight was full and the plane was big.

Both my wife and I thoroughly enjoyed our return home from Tokyo to Auckland and onwards to Palmerston North. We would recommend using the Premier Business class for long-haul travel, any day. Well worth the extra cost. Cabin staff were exceptional, Thank you

This flight was the second leg of a trip that began in Auckland, New Zealand. I was unable to find a way to select seats in advance. The boarding passes we were given in Auckland did not have seat assignments for the second flight. There was no way to check on it until personnel showed up at the gate in Los Angeles, immediately before boarding time. The flight was overbooked by one, and since I was traveling with my sister, we needed two seats. We waited in considerable anxiety for everyone else to board and when one person did not show up, we had to take whatever was left. At least we finally got on the flight although we were the very last to board. We were not able to sit together, of course.

The Premium Economy seats were very comfortable and the food was quite tasty. I did not use the entertainment system, but I was able to charge my phone and tablet with the seatback connection.

We had a cancellation due to weather, but the American Airlines staff was very helpful. Once we got on a plane, the trip was great.

Great food and good entertainment options for the long flight.

It seems that qantas are trying hard to regain their status as Australia's premier airline. I only flew economy but happy with the service entertainment, food, configuration everything.

Loved the food and beverages available, spacious economy class, excellent entertainment

Very good overall. Highly recommend for all flying to Australia

We had bulkhead seats in a A380 in the upper deck in seats 31 D and E. Storage was very limited other than in overhead bin - which is not within reach when in seat. Yet paying same price as others in premium economy who have a lot more storage within arm’s reach. Seems very unfair.

On the Qantas flight, I could barely hear some of the announcements. It was better when I could read them on the screen.

Good check in and helpful staff. Delayed for 1 hour. Took about 45 Mins to get baggage’s at DFW . Food was average ( Hindu meal ) . Overall it was good experience

Our boarding and flight was very good. However when we landed and pulled in to the gate it took 55 minutes for the jet bridge to be positioned next to the aircraft. That caused us to miss our ground transportation and it caused us unnecessary last minute transit planning and expense. Our flight was AA1733 on March 17, 2026

We booked with Qantas instead of Delta and we instead flew on American Airlines. American is not our favorite to go on. No leg room and the width of seats are a joke. Your are packed like sardines on American flights.

Over 5 hour delay with minimal updates or ability to standby for alternative flights. During boarding and 1 hr+ wait for takeoff, seats were drenched w water from air conditioning condensation and always leftover crumbs on carpet and seats

I flew from Barcelona to Chicago on UA yesterday. The flight was on time, the pilots did a great job and the flight attendants were super nice. All of them. Also food was good, and the drinks, including wine were served a few times during our flight. I highly recommend this airline.

Boarded early, left early, arrived 40 mins early! A win win for me!

These airplanes should be illegal. The seats are two tight, it is a safety issue. Wheelchair support was ridiculously slow. We almost missed our flight.

Uncomfortable plastic seats even in premium economy. No free wifi. Even paid wifi was spotty to nonexistent. Bad food. Much worse than economy on foreign carriers like Qantas.

This flight is a quick way to get to Chicago, but a bit expensive.

The clerk at check in for my bags was very rude. My credit card was hacked during my vacation and she told me it was not possible to pay in cash for my bag. “You bought the cheapest ticket, you should have bought a ticket that included a bag. If you cannot pay with a credit card, we will not let you on this flight”. She spoke to her supervisor and then told me , I could ask other passengers, if they would use their credit card to check my bag. I had to beg 5 different people, till one agreed to use their credit card. I payed them cash of course. This was a very stressful and humiliating experience for me. I strongly suggest you build in some kind of provision for travelers who got robbed.

O’hsre taxi and deboarding took 40 minutes. Needed 20 minutes extra time between connecting flights to avoid running through terminal.

Flight crew was super friendly and helpful. Food was frequent and honestly pretty good. Plenty of on-board entertainment. Economy seats are super cramped for such a long flight, but the crew allowed people to get up and stretch, and kids could wander with their parents, so we all made it work. Overall a very good experience.

Standard flight with a drinks and a snack- overall very quick flight. The flight attendants were very strict, bordered on rude.

The flight was good. My luggage didn’t land with me when I arrived in Columbus. So grateful I was able to get my luggage back within the 2 hours😍👍.

gave me complimentary food as the flight was not full and was attentive to my needs

It was a nice and smooth trip. Gave a friendly environment throughout the journey.

Meal and drink service was good. Old plane with old business class seats were quite disappointing

After 3 hours of delays, they ended up cancelling my flight. And although I could purchase one-way tickets to get to my destination, they would not offer me these flights as compensation for the cancelled flight, and I didn't end up making it home until 13 hours after I was originally supposed to arrive. It made for an extremely strenuous end to an otherwise good trip.

It's kindof ridiculous that your system is even asking me about this since my flight was canceled and I wasn't rescheduled.

The flight attendants were not very nice. No smiles On my return trip I was charged for one bag $83.30 although I had purchased the flight including one piece of luggage. Can this be refunded to me? Thank you!

Bad service as well. Another 3hr delayed flight from chicago to Charlotte.

Very bad service the way back we was on the way for r two days very bad condition and waiting for luggage till now

United had no (zero) record of our flight. It took over an hour of us standing in line with surly employee while others waited to get resolved. I have never experienced such poor service and poor empathy.

Everything you need to know for your flight from Sydney to Illinois

Information on your arrival and departure airports