$85 Cheap Flights from Chicago (MDW) to Seattle (SEA)

Find available prices by choosing your travel dates.

Cheap Flights from Chicago to Seattle (MDW-SEA)

Prices were available within the past 7 days and start at $85 for one-way flights and $169 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Southwest Airlines
Southwest Airlines
Southwest Airlines
Southwest Airlines
Frontier Airlines
Southwest Airlines
Frontier Airlines
Frontier Airlines
Southwest Airlines
Delta
Flights from Chicago (MDW) to Seattle (SEA)
Origin airport
Midway Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Delta, Frontier Airlines, Southwest Airlines
Roundtrip price
$169
Distance
1728 mi

Chicago to Seattle Flights

The cheapest times to fly from Chicago to Seattle

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Chicago to Seattle are during the month of July. You can find some of the cheapest flights from Chicago to Seattle with Expedia's search tool and vast selection of airlines.

The best time to book a flight from Chicago to Seattle

Sunday is one of the best days to book for cheap flights from Chicago to Seattle: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

How to find cheap round-trip tickets from Chicago to Seattle

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Chicago to Seattle in 2025. You can also book with separate airlines for your outbound and return journeys, from $85 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Chicago to Seattle flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

You could also save big by booking one of Expedia's vacation packages. Bundling together your Chicago to Seattle airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

*Terms apply.

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

Frequently asked questions

Is it cheaper to buy a plane ticket from MDW to Sea-Tac Airport last minute?
Booking your journey from MDW to SEA at the last minute could save you some dough if you happen to find a real bargain. However, fares don’t usually get cheaper closer to the departure date. If you hold out, flights could also be booked solid or the best seats gone (that could mean the middle seat!). If you’d rather not hedge your bets, book well ahead of the date you want to leave. In fact, you can find some of the biggest deals up to a year in advance. If your preferred carrier hasn’t released its airfares yet, check back regularly as deals are updated on Expedia all the time.
What airports do you fly into for Seattle from Chicago?
From Chicago, you can reach Seattle via Seattle - Tacoma Intl. Airport (SEA), Renton Municipal Airport (RNT) and Boeing Field Airport (BFI). Be sure to check which airport is best for you before making your decision. If you opt for Seattle - Tacoma Intl. Airport (SEA), it’s roughly 12 mi south of downtown. Use the money you save when booking your seat with Expedia to uncover the city’s well-known sights, such as Space Needle and Pike Place Market.
Can I change the date of my flight from Chicago Airport to Seattle - Tacoma Intl. Airport (SEA)?
It’s a piece of cake to make amendments to your Midway Intl. Airport (MDW) to SEA journey yourself. Simply go to the Expedia Trips portal and select “change flight.” Search for new flights and choose the one that fits your plans. You’ll see an estimate of flight change fees that may apply. Alternatively, visit our Customer Service portal to chat to our Virtual Agent and get answers to all your questions.

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*Available to One Key members.