Skip to content
FareTell

Chicago to Ontario flights in May 2027 from $180 MDW, ORD → ONT

Chicago Midway International Airport (MDW), O'Hare International Airport (ORD) → Ontario International Airport (ONT)

For departures in May 2027, the cheapest return found recently is $427 with Southwest Airlines, 26 May 2027 – 10 Jun 2027, found 6 days ago. The cheapest one-way found recently is $180 with Southwest Airlines, 11 May 2027, found 3 days ago.

Return

We hold return fares on only 1 departure date in May 2027, too few to say what one usually costs.

Cheapest return found recently

$427

26 May 2027 – 10 Jun 2027 · Southwest Airlines

Chicago Midway International Airport (MDW) → Ontario International Airport (ONT)

out nonstop, back 1 stop

found 6 days ago

See prices for these datesCheck today's price

It is also the cheapest return we hold, of any age.

FareTell may earn a commission when you book through a partner.

The cheapest dates in May 2027

DatesFromAirlineStopsFound
26 May 2027 – 10 Jun 2027$427Southwest Airlinesout nonstop, back 1 stopfound 6 days agoSee prices for these dates

Every date we hold

1 departure date

See every date as a table
The cheapest price seen for each departure date — per traveler in Economy.
DatesFromAirlineAirportsStopsFound
26 May 2027 – 10 Jun 2027$427Southwest AirlinesChicago Midway International Airport (MDW) → Ontario International Airport (ONT)out nonstop, back 1 stopfound 6 days agoSee prices for these dates

Which month looks cheapest?

December 2026 is the cheapest month — from $189.

November 2026From $2542 departure dates15 Nov – 17 Nov · found 4 days agoSee prices for these dates
December 2026From $189Cheapest seen4 departure dates10 Dec – 8 Jan 2027 · found 7 days agoSee prices for these dates
February 2027From $2611 departure date12 Feb 2027 – 21 Feb 2027 · found 7 days agoSee prices for these dates
March 2027From $3811 departure date8 Mar 2027 – 14 Mar 2027 · found 4 days agoSee prices for these dates
April 2027From $4741 departure date1 Apr 2027 – 4 Apr 2027 · found 5 days agoSee prices for these dates
May 2027From $4271 departure date26 May 2027 – 10 Jun 2027 · found 6 days agoSee prices for these dates
June 2027From $3921 departure date1 Jun 2027 – 4 Jun 2027 · found 7 days agoSee prices for these dates

One-way

In May 2027, the cheapest one-way fare on each of 7 departure dates is usually $181 to $207. Across all 14 departure dates we hold on this route, it is usually $139 to $199.

Cheapest one-way found recently

$180

11 May 2027 · Southwest Airlines

Chicago Midway International Airport (MDW) → Ontario International Airport (ONT)

nonstop

found 3 days ago

Open this tripCheck today's price

Cheapest we hold, of any age

$179

25 May 2027 · Alaska Airlines

O'Hare International Airport (ORD) → Ontario International Airport (ONT)

1 stop

found 5 days ago

Open this tripCheck today's price

FareTell may earn a commission when you book through a partner.

The cheapest dates in May 2027

DatesFromAirlineStopsFound
25 May 2027$179Alaska Airlines1 stopfound 5 days agoOpen this trip
11 May 2027$180Southwest Airlinesnonstopfound 3 days agoOpen this trip
26 May 2027$182Southwest Airlinesnonstopfound 5 days agoOpen this trip
13 May 2027$204Southwest Airlines1 stopfound 5 days agoOpen this trip
10 May 2027$206Southwest Airlines1 stopfound 3 days agoOpen this trip

Every date we hold

7 departure dates

10 May 2027: $206, found 3 days ago11 May 2027: $180, found 3 days ago13 May 2027: $204, found 5 days ago25 May 2027: $179, found 5 days ago26 May 2027: $182, found 5 days ago28 May 2027: $234, found 3 days ago29 May 2027: $207, found 5 days agoMay
See the chart as a table
The cheapest price seen for each departure date — per traveler in Economy.
DatesFromAirlineAirportsStopsFound
10 May 2027$206Southwest AirlinesChicago Midway International Airport (MDW) → Ontario International Airport (ONT)1 stopfound 3 days agoOpen this trip
11 May 2027$180Southwest AirlinesChicago Midway International Airport (MDW) → Ontario International Airport (ONT)nonstopfound 3 days agoOpen this trip
13 May 2027$204Southwest AirlinesChicago Midway International Airport (MDW) → Ontario International Airport (ONT)1 stopfound 5 days agoOpen this trip
25 May 2027$179Alaska AirlinesO'Hare International Airport (ORD) → Ontario International Airport (ONT)1 stopfound 5 days agoOpen this trip
26 May 2027$182Southwest AirlinesChicago Midway International Airport (MDW) → Ontario International Airport (ONT)nonstopfound 5 days agoOpen this trip
28 May 2027$234United AirlinesO'Hare International Airport (ORD) → Ontario International Airport (ONT)nonstopfound 3 days agoOpen this trip
29 May 2027$207Southwest AirlinesChicago Midway International Airport (MDW) → Ontario International Airport (ONT)1 stopfound 5 days agoOpen this trip

Which month looks cheapest?

December 2026 is the cheapest month — from $99.

November 2026From $1281 departure date19 Nov · found 8 days agoSee prices for these dates
December 2026From $99Cheapest seen1 departure date7 Dec · found 7 days agoOpen this trip
January 2027From $1251 departure date25 Jan 2027 · found 3 days agoOpen this trip
February 2027From $1312 departure dates1 Feb 2027 · found 5 days agoOpen this trip
May 2027From $1797 departure dates25 May 2027 · found 5 days agoOpen this trip
July 2027From $1741 departure date15 Jul 2027 · found 6 days agoOpen this trip
August 2027From $1741 departure date8 Aug 2027 · found 6 days agoOpen this trip

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