Ontario to Chicago ONT → MDW, ORD
Ontario International Airport (ONT) → Chicago Midway International Airport (MDW), O'Hare International Airport (ORD)
The cheapest return found recently is $239 with Frontier Airlines, 1 Nov – 3 Nov, found yesterday. The cheapest one-way found recently is $217 with Alaska Airlines, 20 Aug 2027, found yesterday.
Return
The cheapest return fare on each of 4 departure dates is usually $242 to $289.
Cheapest return found recently
$239
1 Nov – 3 Nov · Frontier Airlines
Ontario International Airport (ONT) → O'Hare International Airport (ORD)
Leaves 6:25 a.m. · Return leaves 6:30 a.m. · 22 h 1 min of travel, both ways together
out 1 stop, back 1 stop
found yesterday
Cheapest nonstop return
$305
1 Feb 2027 – 4 Feb 2027 · American Airlines
Ontario International Airport (ONT) → O'Hare International Airport (ORD)
Leaves 6:26 a.m. · Return leaves 6:00 a.m. · 8 h 46 min of travel, both ways together
out nonstop, back nonstop
found 3 days ago
Found recently, and the cheapest we hold
$239 1 Nov – 3 Novfound yesterdaySee prices for these dates
It is also the cheapest return we hold, of any age.
What have prices looked like?
Over 25 days, 24 Sept to 18 Oct, the cheapest return we saw each day was $157 to $243.
25 days is a short history, so treat this range as an early guide.
Those were the prices on those days, not today's.
Is this a good return price?
Compared with the cheapest return fare on each of 4 departure dates from 20 Oct to 1 Feb 2027, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
We hold no other 2-night return fares leaving within 3 days of 1 Nov to compare.
Every date we hold
5 fares on 4 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 20 Oct – 22 Oct | $283 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | out 1 stop, back 1 stop | found 2 days ago | See prices for these dates |
| 1 Nov – 3 Nov | $239 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | out 1 stop, back 1 stop | found yesterday | See prices for these dates |
| 15 Jan 2027 – 22 Jan 2027 | $243 | Southwest Airlines | Ontario International Airport (ONT) → Chicago Midway International Airport (MDW) | out nonstop, back nonstop | found 4 days ago | See prices for these dates |
| 1 Feb 2027 – 4 Feb 2027 | $305 | American Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | out nonstop, back nonstop | found 3 days ago | See prices for these dates |
Which month looks cheapest?
November 2026 is the cheapest month — from $239.
Airlines on the cheapest dates: Frontier Airlines, Southwest Airlines, American Airlines.
One-way
The cheapest one-way fare on each of 11 departure dates is usually $119 to $140.
Cheapest one-way found recently
$217
20 Aug 2027 · Alaska Airlines
Ontario International Airport (ONT) → O'Hare International Airport (ORD)
Leaves 7:41 p.m. · 8 h 33 min trip
1 stop
found yesterday
Cheapest nonstop one-way
None seen yet.
Found recently, and the cheapest we hold
$217 20 Aug 2027found yesterdayOpen this trip
$114 23 Octfound 6 days agoOpen this trip
What have prices looked like?
Over 25 days, 24 Sept to 18 Oct, the cheapest one-way we saw each day was $88 to $125.
At $217, the cheapest one-way found recently is above that range.
25 days is a short history, so treat this range as an early guide.
Those were the prices on those days, not today's.
Is this a good one-way price?
Compared with the cheapest one-way fare on each of 11 departure dates from 20 Oct to 20 Aug 2027, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
We hold no other one-way fares leaving within 3 days of 20 Aug 2027 to compare.
Every date we hold
11 fares on 11 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 20 Oct | $115 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 2 days ago | Open this trip |
| 22 Oct | $146 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 6 days ago | Open this trip |
| 23 Oct | $114 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 6 days ago | Open this trip |
| 24 Oct | $119 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 5 days ago | Open this trip |
| 26 Oct | $119 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 2 days ago | Open this trip |
| 27 Oct | $119 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 2 days ago | Open this trip |
| 31 Oct | $119 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 3 days ago | Open this trip |
| 1 Nov | $133 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 3 days ago | Open this trip |
| 20 Nov | $132 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 5 days ago | Open this trip |
| 3 Jan 2027 | $234 | Frontier Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found 6 days ago | Open this trip |
| 20 Aug 2027 | $217 | Alaska Airlines | Ontario International Airport (ONT) → O'Hare International Airport (ORD) | 1 stop | found yesterday | Open this trip |
Which month looks cheapest?
October 2026 is the cheapest month — from $114.
Airlines on the cheapest dates: Frontier Airlines, Alaska Airlines.
Premium cabin fares from Ontario to Chicago
We hold no premium economy, business or first-class fares for this route: we collect them for the busiest routes, and this one is not among them yet.
Today's prices for 1 Nov – 3 Nov in another cabin: Premium economy · Business · First
Today's prices for 20 Aug 2027 in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for Ontario to Chicago?
Return
Fares 30 to 59 days before departure were typically 24% lower than 0 to 6 days before departure.
From the cheapest return each day between 24 Sept and 18 Oct (25 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 0–6 days | $266 | $161 | +32% | 25 |
| 7–13 days | $233 | $202 | +15% | 23 |
| 14–29 days | $210 | $157 | +4% | 24 |
| 30–59 days | $202 | $200 | Cheapest seen | 23 |
| 60–89 days | $274 | $215 | +36% | 21 |
| 90–179 days | $273 | $243 | +35% | 25 |
One-way
The cheapest fares were 30 to 59 days before departure.
From the cheapest one-way each day between 24 Sept and 18 Oct (25 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 0–6 days | $122 | $99 | +3% | 23 |
| 7–13 days | $124 | $114 | +5% | 25 |
| 14–29 days | $122 | $88 | +3% | 20 |
| 30–59 days | $118 | $104 | Cheapest seen | 20 |
| 60–89 days | $140 | $124 | +19% | 16 |
| 90–179 days | $189 | $189 | +60% | 8 |
| 180+ days | $214 | $159 | +81% | 14 |
Could a nearby airport be cheaper?
A different airport at either end can change the fare — sometimes a lot.
Return
Los Angeles → Chicago
56 km from Ontario
$332
$93 more than flying from Ontario
1 Nov – 3 Nov · LAX → ORD · out 1 stop, back 1 stop
found yesterday
Long Beach → Chicago
60 km from Ontario
$435
$196 more than flying from Ontario
1 Nov – 3 Nov · LGB → MDW · out nonstop, back 1 stop
found yesterday
Cheapest recent price on each route — round trip, per traveler in Economy. Distances are in a straight line.
One-way
Los Angeles → Chicago
56 km from Ontario
$204
$13 less than flying from Ontario
20 Aug 2027 · SNA → ORD · 1 stop
found yesterday
Long Beach → Chicago
60 km from Ontario
$221
$4 more than flying from Ontario
20 Aug 2027 · LGB → ORD · 1 stop
found yesterday
Cheapest recent price on each route — one way, per traveler in Economy. Distances are in a straight line.
Live price for these dates
The cheapest return found recently is for 1 Nov – 3 Nov. A live search on this page shows what those dates cost now, for one adult in economy.
Prices are what travelers' searches on Aviasales found in the last 7 days, in US dollars: the price the seller showed on Aviasales; bags may cost extra. Fares change, so check today's price before you book. How our prices work