Cheap flights from Illinois to Seattle from $55
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Illinois to Seattle departing on 9/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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How to get the cheapest flight ticket from Illinois to Seattle
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to Seattle?
In general, February is the cheapest month to fly from Illinois to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $214. If you don’t want to visit Seattle in February, then you should wait until September to fly from Illinois, when ticket prices are also cheap, with an average price of $226.
What is the cheapest day to depart on your flight to Seattle?
On average, the least expensive day to fly to Seattle from Illinois is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $331. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Illinois because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $440.
What is the cheapest time of day to depart on your flight to Seattle?
Flying to Seattle from Illinois in the evening is the least expensive time of day to depart. momondo users have found prices as low as $326 when looking at flights departing in the evening. Flights to Seattle are more costly at noon, with an average ticket price of $384. Departure times at noon fall within the peak daily travel times, which is why tickets can be more expensive.
What is the cheapest Illinois to Seattle/Tacoma Intl flight route?
Fly from Chicago Midway to Seattle/Tacoma Intl for the best Illinois - Seattle/Tacoma Intl flight prices
How far in advance should I book a flight to Seattle?
You are more likely to see cheaper flights to Seattle from Illinois when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $284 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Illinois for as low as $245 on momondo.
What cabin class options are available on Illinois to Seattle/Tacoma Intl flights?
There are 4 cabin classes available to choose from on Illinois to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
What is the cheapest airline that flies from Illinois to Seattle/Tacoma Intl?
Southwest, Alaska Airlines, and United Airlines are the most popular carriers operating from Illinois to Seattle/Tacoma Intl
What airlines fly to Seattle?
Alaska Airlines, Delta and American Airlines are the top three most popular airlines that fly to Seattle from Illinois according to our data. Alaska Airlines is the first choice among our users, with 34% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 8 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.
How many flights depart from Illinois to Seattle on average per day?
70 flights are operational daily from Illinois to Seattle as of June 2025. The most popular departure time for this route is 5:00PM, with 36% of flights per day taking off at noon.
How many flights depart from Illinois to Seattle on average per week?
As of June 2025, there are 496 flights per week flying from Illinois to Seattle. The most common day of the week flights depart is Mon, with 18% of flights taking off on this day.
Cheap Illinois to Seattle flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Illinois to Seattle
When did momondo last update prices for flights from Illinois to Seattle/Tacoma Intl Airport?
Prices for flights from Illinois to Seattle/Tacoma Intl Airport refresh daily.
How many operators does momondo search for flights from Illinois to Seattle/Tacoma Intl Airport?
As of June 2025, there are 8 operators available to choose from for flights from Illinois to Seattle/Tacoma Intl Airport.
How old do you have to be to fly from Illinois to Seattle/Tacoma Intl Airport?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Illinois to Seattle/Tacoma Intl Airport.
What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?
The required travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from Illinois to Seattle?
momondo data reveals that the most frequently booked plane model on the route from Illinois to Seattle is Boeing 737-900 Passenger/BBJ3 (winglets), representing 18.89% of all bookings. The subsequent popular models are Boeing 737-800 Passenger/BBJ2 (winglets) at 14.10%, Boeing 737-800 at 13.44%, and Boeing 737 MAX 8 at 9.71%.
Best airlines flying from Illinois to Seattle
Compare and see reviews for airlines that fly from Illinois to Seattle with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $89 | Free Cancellation | Rating 7.8 2,507 reviews | |||
| PriceFrom $105 | Free Cancellation | Rating 6.3 8,066 reviews | |||
| PriceFrom $118 | Free Cancellation | Rating 5.9 3,301 reviews | |||
| PriceFrom $135 | Free Cancellation | Rating 8.0 7,964 reviews | |||
| PriceFrom $156 | Free Cancellation | Rating 8.0 10,000 reviews | |||
| PriceFrom $163 | Free Cancellation | Rating 7.4 8,810 reviews | |||
| PriceFrom $169 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $199 | Free Cancellation | Rating 8.0 4,280 reviews |
Traveling to a place near Seattle?
Book flights to Seattle if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Illinois to Seattle?
Finding the right flight to Seattle from Illinois is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Seattle quick and easy, saving you time and money.
Can I find flights from Illinois to Seattle with flexible booking policies on momondo?
Yes. momondo enables you to select and highlight flights to Seattle from Illinois with this policy.
How can momondo help me find flights from Illinois to Seattle?
Once you have performed a search for Illinois to Seattle flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.
I’m not ready to book a flight from Illinois to Seattle right now. Can momondo alert me if prices change?
If you are not ready to book a flight from Illinois to Seattle now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Seattle and let you know when they change.