$171 Cheap Flights from Champaign (CMI) to Seattle (SEA)

View $171 flight on Wed, Aug 27, 2025Opens in a new window

Popular airlines from Champaign, IL (CMI-University Of Illinois Urbana-Champaign Williard) to Seattle-Tacoma International Airport (SEA)

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Cheap Flights from Champaign to Seattle (CMI-SEA)

Prices were available within the past 7 days and start at $171 for one-way flights and $284 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Tue, Oct 21 - Thu, Oct 30
CMI
Champaign
SEA
Seattle
$284 Roundtrip, found 3 hours ago
$284
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Tue, Oct 21 from Champaign to Seattle, returning Thu, Oct 30, priced at $284 found 3 hours ago
American Airlines
Thu, Dec 11 - Mon, Dec 29
CMI
Champaign
SEA
Seattle
$306 Roundtrip, found 3 hours ago
$306
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Thu, Dec 11 from Champaign to Seattle, returning Mon, Dec 29, priced at $306 found 3 hours ago
American Airlines
Mon, Apr 27 - Tue, May 5
CMI
Champaign
SEA
Seattle
$328 Roundtrip, found 1 day ago
$328
Roundtrip
found 1 day ago
Select American Airlines flight, departing Mon, Apr 27 from Champaign to Seattle, returning Tue, May 5, priced at $328 found 1 day ago
American Airlines
Sat, Apr 18 - Mon, Apr 20
CMI
Champaign
SEA
Seattle
$342 Roundtrip, found 4 days ago
$342
Roundtrip
found 4 days ago
Select American Airlines flight, departing Sat, Apr 18 from Champaign to Seattle, returning Mon, Apr 20, priced at $342 found 4 days ago
American Airlines
Thu, Dec 11 - Mon, Dec 29
CMI
Champaign
SEA
Seattle
$356 Roundtrip, found 3 hours ago
$356
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Thu, Dec 11 from Champaign to Seattle, returning Mon, Dec 29, priced at $356 found 3 hours ago
American Airlines
Tue, Oct 21 - Thu, Oct 30
CMI
Champaign
SEA
Seattle
$374 Roundtrip, found 3 hours ago
$374
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Tue, Oct 21 from Champaign to Seattle, returning Thu, Oct 30, priced at $374 found 3 hours ago
American Airlines
Thu, Dec 11 - Mon, Dec 29
CMI
Champaign
SEA
Seattle
$378 Roundtrip, found 3 hours ago
$378
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Thu, Dec 11 from Champaign to Seattle, returning Mon, Dec 29, priced at $378 found 3 hours ago
American Airlines
Sat, Apr 18 - Mon, Apr 20
CMI
Champaign
SEA
Seattle
$385 Roundtrip, found 4 days ago
$385
Roundtrip
found 4 days ago
Select American Airlines flight, departing Sat, Apr 18 from Champaign to Seattle, returning Mon, Apr 20, priced at $385 found 4 days ago
American Airlines
Wed, Aug 20 - Tue, Aug 26
CMI
Champaign
SEA
Seattle
$387 Roundtrip, found 4 days ago
$387
Roundtrip
found 4 days ago
Select American Airlines flight, departing Wed, Aug 20 from Champaign to Seattle, returning Tue, Aug 26, priced at $387 found 4 days ago
American Airlines
Tue, Oct 21 - Thu, Oct 30
CMI
Champaign
SEA
Seattle
$395 Roundtrip, found 3 hours ago
$395
Roundtrip
found 3 hours ago
Select American Airlines flight, departing Tue, Oct 21 from Champaign to Seattle, returning Thu, Oct 30, priced at $395 found 3 hours ago

Find the cheapest month to fly from Champaign (CMI) to Seattle (SEA)

September is typically the cheapest month to fly

From $198 - $796 per traveler.

Graph displaying average flight prices per month

Alternative airports near Seattle

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Seattle - Tacoma Intl. SEA. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $400
SEA
Seattle - Tacoma Intl.
Cheapest
Average driving time to city center20 min
Flights from $400
Flights from Champaign (CMI) to Seattle (SEA)
Origin airport
University Of Illinois Urbana-Champaign Williard
Destination airport
Seattle - Tacoma Intl.
Airlines serving
American Airlines
Roundtrip price
$284
Distance
1758 mi

Champaign to Seattle Flights

The cheapest times to fly from Champaign 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 Champaign to Seattle are during the month of October. You can find some of the cheapest flights from Champaign to Seattle with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Champaign to Seattle

Sunday is one of the best days to book for cheap flights from Champaign 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 Champaign 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 Champaign to Seattle in 2025. You can also book with separate airlines for your outbound and return journeys, from $171 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 Champaign 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 Champaign 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

How much does a flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA) cost?
Grab a cheap one-way flight from $171 or cheap return flight from $284 from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight offers on this route.
What is the cheapest month to fly from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA)?
Traveling in October is a great way to save, as it's the cheapest month for flights between CMI and SEA. You'll typically find the lowest fares during off-peak months.
How many flights per day from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA)?
You'll need to catch a flight with a layover if you're traveling from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA). Direct flights don't operate daily on this route. However, simply filter your search to include one or two stops to find an option that works for you.
What day of the week has the most flights from CMI to SEA?
Usually you'll find the widest variety of flight choices on a Friday. Tuesdays are often the quietest.* However, this can vary depending on the time of year, carrier and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA)?
To reach Seattle - Tacoma Intl. Airport (SEA) on schedule, select a flight that leaves University Of Illinois Urbana-Champaign Williard Airport (CMI) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this hour.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA) last-minute?
Booking your flight from CMI to SEA just before your getaway is typically more expensive. But if you're flexible with your travel times and dates, you could bag a cheap last-minute fare.
Is it cheaper to book a CMI to SEA flight and hotel package?
Booking a CMI to SEA flight and hotel package is generally cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your trip all in one place. Choose from our extensive range of accommodations and then add car rentals, flights and activities to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Seattle - Tacoma Intl. Airport (SEA)?
If you reserved your CMI to SEA flight within the last 24 hours, you may be able to cancel or modify it without any fees. Depending on the airline and the fare type you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more details.

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*Available to One Key members.