$922 Find Cheap Flights from Sydney to Illinois

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 9/10. 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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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

Wed, 20 May - Thu, 28 May
Multiple Airlines Logo
09:20 - 12:06
SYD
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STL
41h 46m
2 stops
Multiple Airlines Logo
16:48 - 07:20
STL
-
SYD
23h 32m
2 stops
$1,483Multiple Airlines
Mon, 10 Aug - Thu, 3 Sep
Air Canada Logo
09:20 - 20:39
SYD
-
STL
50h 19m
2 stops
Air Canada Logo
05:10 - 07:20
STL
-
SYD
35h 10m
2 stops
$1,510Air Canada
Mon, 10 Aug - Thu, 3 Sep
Air Canada Logo
09:20 - 16:31
SYD
-
STL
46h 11m
2 stops
Air Canada Logo
05:10 - 07:20
STL
-
SYD
35h 10m
2 stops
$1,512Air Canada
Wed, 20 May - Thu, 28 May
Air Canada Logo
09:20 - 20:25
SYD
-
STL
26h 05m
2 stops
Air Canada Logo
13:05 - 07:20
STL
-
SYD
51h 15m
3 stops
$1,544Air Canada
Wed, 20 May - Thu, 28 May
Multiple Airlines Logo
09:20 - 12:06
SYD
-
STL
41h 46m
2 stops
Multiple Airlines Logo
16:48 - 07:20
STL
-
SYD
23h 32m
2 stops
$1,615Multiple Airlines
Wed, 20 May - Thu, 28 May
Air Canada Logo
09:20 - 20:25
SYD
-
STL
26h 05m
2 stops
Air Canada Logo
07:05 - 07:20
STL
-
SYD
33h 15m
2 stops
$1,626Air Canada
Sun, 14 Jun - Sun, 21 Jun
Air Canada Logo
09:20 - 20:25
SYD
-
STL
50h 05m
2 stops
Air Canada Logo
13:20 - 07:20
STL
-
SYD
51h 00m
2 stops
$1,663Air Canada
Thu, 4 Jun - Wed, 12 Aug
Delta Logo
09:15 - 18:33
SYD
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MDW
24h 18m
2 stops
Delta Logo
13:00 - 06:50
MDW
-
SYD
26h 50m
2 stops
$2,353Delta
Mon, 25 May - Mon, 1 Jun
Delta Logo
09:15 - 17:56
SYD
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MDW
23h 41m
2 stops
Delta Logo
10:59 - 06:50
MDW
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SYD
28h 51m
2 stops
$2,356Delta
Thu, 4 Jun - Wed, 12 Aug
Delta Logo
09:15 - 17:56
SYD
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MDW
23h 41m
2 stops
Delta Logo
14:00 - 06:50
MDW
-
SYD
25h 50m
2 stops
$2,359Delta
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 May.

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 $650 (return) on average. On the other hand, the most expensive months are February and January, when the average cost of return tickets is $1,201 and $1,169 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 22% compared to booking last-minute. For the absolute cheapest price, our data suggests you should book 6 weeks before departure.

Good to know

Low seasonMarch
Cheapest flight$922
Best time to beat the crowds (6% less expensive on average)
Most popular time to fly (5% 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.
8.0
Air New ZealandOverall score based on 639 reviews
8.0Comfort
7.4Entertainment
7.4Food
8.5Crew
8.2Boarding
Airline reviews

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

8.0 ExcellentAnonymous, Apr 2026
LFT - IAH
Read more Air New Zealand reviews

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.

Great service. Food could be improved but overall a very good airline

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 difficulty checking in as United didn’t recognize the confirmation number and the agent was not helpful. We went to the United Assistance desk where the agent was able to process our reservation. We also weren’t allowed to choose seats in advance.

Your entertainment could be better. I flew on Air New Zealand in January so was expecting a better choice in February...but no luck. Same choices and also could have a better selection. Otherwise, lovely service, the purser came to our seats to welcome us. Overall, very nice. Direct flight from Auckland to YVR was fantastic!

Air New Zealand over sold our flight and tried to bump us to yesterday. After several calls we got booked to United about 6 hrs before our original flight. No apologies!

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.

When I originally booked this flight, I was expecting to travel on Qantas. When the itinerary changed and the long-haul segment was operated by American Airlines, we were disappointed but remained open-minded. Unfortunately, the overall service experience fell far short of expectations. This was a long-haul international flight. Getting up periodically to use the restroom or stretch is inevitable, especially on flights of this duration. However, each time we stood up, we felt as though we were inconveniencing the crew. The tone and body language often suggested that we were in the way or disrupting something simply by moving about the cabin. As a result, I avoided getting up as often as I needed to and was physically very sore upon arrival. Meal service was similarly impersonal. The options were presented in single words “beef or veggie,” “pasta or beef” without any description of what was actually being served. There was little engagement or courtesy beyond that. Even simple expressions of gratitude were often not acknowledged. I am accustomed to no-frills travel and do not expect luxury. What was disappointing was not the absence of extras, but the absence of basic warmth and professionalism. On a long-haul international flight, small moments of courtesy and humanity make a significant difference. In this case, the experience felt transactional and dismissive rather than welcoming. I hope this feedback is taken constructively, as there is a meaningful difference between efficient service and indifferent service.

Flight arrived late with no one to help over 30 people rebook. I slept at the airport.

Business seats not as comfortable or private as most competitors (e.g. Qantas was outstanding), and movie selection was much more limited than Qantas or United has been recently

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.

Starlink is great Crew was polite Business class didn’t get a welcome drink just water and snacks were ok

Delayed - weather wasn't bad at either end. Also sat on tarmac in ORD.

very average service no complimentary alcoholics drinks unlike other airlines such as Porter airlines No decent seats available during check-in time the day before

boarded early to only find out that flight would sit at gate for 45 min to an hour. Landed in chicago and sat on runway for over an hour before got to gate. Total delay was extensive for a 45 min flight door to door.

The flight was significantly delayed. The inbound flight from EWR was delayed departing because of mechanical problems. My original departure from CLT was 5:28 pm but due to the delay of the inbound flight, after arrival, deplaning, cleaning, boarding, we did not push back from the gate until 9:00 pm. Once in the air, the flight was smooth and what was originally supposed to be an arrival in ORD at 7:30 pm local time turned out to be 9:35 pm.

The flight I was supposed to be on was supposed to take off at 1:50 from State College. It was delayed over and over and over again until somehow I had to rebook on a flight that was supposed to have left State College at 8 am that morning but didn't end up taking off until almost 6 pm. Not only was this completely unacceptable, the "token from United" was a 15 dollar meal voucher that has to be used by today. I would personally like some miles added to my account for this inconvenience. I was in transit for 8 hours from the time I arrive at State College Aiport to when I got home. I was supposed to be home at 3 pm and I returned at 8 pm. Unacceptable. I have not been on an on Time united flight in nearly 5 years.

newer aircraft, ability to connect my headset via blue tooth for entertainment.

Very comfortable flight, snacks and drinks were good, good communication from crew. Could have used a little more information on timing of boarding for group 5

It was good, the staff was great, and the food, was as usual, tea and biscuit. Bathroom was clean, and the plane was clean as well.

Very good I can’t complain one bit. Thank you American Airlines for making my flight enjoyable and safe!

The staff and service on American Airlines were truly outstanding. I had requested wheelchair assistance for my mother due to her knee issues, and the team went above and beyond every step of the way—from boarding in Boston to our arrival in Chicago. Their care, professionalism, and attentiveness made the entire experience smooth and stress-free. I’m very grateful for the support they provided.

The new planes (American Eagle) are beautiful and especially comfortable. The flight attendants are consistently professional and courteous. And, while it may seem inconsequential, the new liquid tube of coffee creamer—in contrast to the powdered coffee creamer—makes all the difference in a cup of coffee.

Boarding was quick and efficient. We arrived at our destination early.

I'm not sure American is capable of on-time arrivals and departures. When you land at ORD, you almost always get held on the tarmac because your gate is still occupied. I may have missed my connection, but that ended up up being significantly delayed as well. Once again, I finally got home well after midnight.

Didn't make it back on American Airlines due to a maintenance issue. The communication and updates were terrible. I ended up returning on Aero Mexico which had a much nicer aircraft with a large entertainment screen with movies and shows AND they had a nice inflight meal. That was a treat after being delayed 26 hours! I think some additional flight miles, or something should be offered for that long of a delay ---it was not pleasant at all---very physical and emotional experience.

Crew at the gate was very crabby and not at all polite. The plane was very hot the entire flight. And the seat cushion was very worn out.

The staff are very, very professional. It's what flying should feel like.

Flight was delayed half hour before boarding, but when I checked flight aware the plane that would Pick us up had a delay of more than an hour. AA should let us know in advance to avoid waiting several hours in the airport

Flight itself was not bad at all. However: my checked bag (checked in Calgary) did not make it onto this flight as I found out after I landed at EWR. I still don't have it but it appears that it is on its way to me.

Flight and attendance were very good we had 2 hour delay that took the shine of it

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.

Be careful about the bad policy and when purchasing seats

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.

Or the greatest and it ended up picking us up from Chicago to Toronto not sure who was tesponsible for the 4 hr delay. United should have been properly prepared for a scheduled flight from Austin to Chicago and they were not.

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

Information on your arrival and departure airports