Cheapest€230.83
- United Airlines UA639306:474h10:47Ontario ONTChicago ORD
Door to door 7h 10mCO2 697.4 kgChanges 0Fixed, no changes
Ontario to Chicago flight
Flights from Ontario to Chicago start at €274.49 and take 7h 10m at their fastest.
The Flights from Ontario to Chicago starts at €274.49 and takes 7h 10m door to door, run by 2 operators over 2,835 km, with around 8 departures a day. Fares bottom out about 45 days before departure.
- 7h 10mDoor to door
- 4hMoving
- €274.49From
- 697.4 kgCO2
The cheapest and the fastest on September 28, 2026
Two journeys we can sell today, with the service number each operator files them under.
Lowest CO2€276.85
- Bahamasair B813007:304h 10m11:40Ontario ONTRockford RFD
- Amtrak A653112:5059m13:49RockfordChicago Union Station
Changes at Rockford, with 70 minutes between services and a walk of about 14 minutes.
Door to door 8h 16mCO2 673.8 kgChanges 1Fixed, no changes
Airlines
Speed, flexibility and what is on board. Nothing here is a rating, because we have not earned one.
| Operator | From |
|---|---|
| United Airlines | €230.83 |
 Southwest Airlines | €238.50 |
Chicago sits on the water, which usually settles which side of town you want to wake up on. Rooms are not ours to sell.
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When to book Ontario to Chicago
The same search run across the whole booking window, so the shape of the curve is visible rather than described.
- €278.6290 days
- €180.6860 days
- €177.7345 days
- €187.1730 days
- €291.0121 days
- €368.3014 days
- €343.527 days
- €343.523 days
- €518.751 days
- Cheapest lead time
- Fares bottom out around 45 days ahead, at €177.73.
- How much it moves
- The gap between the cheapest and most expensive lead time is 192 percent. The most expensive point is €518.75, 1 days out.
- What that means
- Today sits inside the cheap window, which closes about 45 days before departure. Waiting from here has usually cost money on this corridor rather than saved it.
Which departure day costs least
Median cheapest fare for each weekday, taken across the next three weeks of real prices.
- €330.54Sun
- €312.25Mon
- €274.49Tue
- €311.07Wed
- €374.20Thu
- €371.84Fri
- €343.52Sat
Where you leave from and where you arrive
The stations, airports and ports each mode on this corridor actually uses.
Ontario
Air
- ONT
Chicago
Air
- ORD
- MDW
What the journey actually looks like
Direct or connecting, how far the route really runs, and what happens when a connection is missed.
- Direct or connecting
- 50% of the services we sell on this corridor run through without a change. The remaining 50% involve one connection.
- How far it really runs
- The route covers 2,835 km against 2,753 km in a straight line, a detour of 3 percent. Track and road geometry account for the difference.
- Where the change is
- Connections are made at Albuquerque, Rockford, Denver, Las Vegas. The gap between arriving and leaving is 54 minutes, of which about 5 is walking.
- If the connection is missed
- The tightest connection we sell here has a 17 percent chance of not being made on the timetable alone. Part of this journey is a self transfer between separate tickets, so leave more time than the minimum and expect to check in again.
- First and last departure
- The first service of the day leaves Ontario at 06:47 and the last at 14:39, across 8 departures. The return direction keeps its own timetable, so the times back are not these times reversed.
Questions about Ontario to Chicago
The questions people actually ask about this trip, answered from the same prices and times the page above is built on rather than written once and left to go stale.
How long does the Flight from Ontario to Chicago take?
The Flight from Ontario to Chicago takes 7h 10m door to door, of which 4h is spent moving. The route runs 2,835 km. The difference between the two times is reaching the terminal and leaving it at the far end, which every time on this page includes.
How much does the Flight from Ontario to Chicago cost?
The Flight from Ontario to Chicago starts at €274.49 for one passenger, checked on September 28, 2026. A typical fare is €273.31. Both are the total including taxes, supplier fees and our service fee, so the price here is the price at checkout.
Who runs the Flight from Ontario to Chicago?
2 operators run the Flight from Ontario to Chicago: United Airlines, Southwest Airlines. Between them they file around 8 departures a day. The operator table on this page compares them on fare, journey time, cruising speed, fare conditions and what is provided on board.
Which terminal does the Flight from Ontario to Chicago use?
The Flight from Ontario to Chicago leaves from Ontario ONT and arrives at Chicago ORD. Allow about 3h 10m for reaching the departure terminal and leaving the arrival one. That time is already inside every door to door figure quoted on this page.
When should I book the Flight from Ontario to Chicago?
Fares for the Flight from Ontario to Chicago bottom out around 45 days ahead, at €177.73. The gap between the cheapest and most expensive lead time across the window is 192 percent, measured on September 28, 2026. Booking inside the final week has consistently cost more.
How much CO2 does the Flight from Ontario to Chicago produce?
The Flight from Ontario to Chicago produces about 697.4 kg of CO2 per passenger over 2835 km, which works out at roughly 246 grams per passenger kilometer. That figure is for the whole journey and for one traveler, not for the vehicle.
Where these numbers come from
Observed service A carrier record shows this named operator serving this named pair, and we carry that through unchanged.
Schedules, seat counts and fares are generated by our own model until the supplier contracts are signed. Places, coordinates, operators, which operator serves which pair, and every distance are real. We would rather say that on every page than let a modeled number pass for a filed one.
Defined in full at Door to door, Fares, The booking window, Carbon
- On this page
- Every figure above was computed for Ontario to Chicago on September 12, 2026: 2835 km of route against 2753 km in a straight line, 8 services a day, 2 operators, a cheapest fare of €274.49, and 7h 10m door to door on the fastest mode. The return direction is computed separately and its numbers are not these numbers.
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