Cheap flights from Seattle to Illinois from $52
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Illinois departing on 9/16. 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 Seattle to Illinois
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 Illinois?
The cheapest month to fly to Illinois from Seattle is in January. Flight prices, which tend to average around $223, are often lower during this time because this is during the off-season. If you aren’t able to travel to Illinois during the month of January, then flying in September is also cheap. Prices for this month can be found on momondo for an average of $247.
What is the cheapest day to depart on your flight to Illinois?
The cheapest day to depart from Seattle to Illinois is on a Wednesday when prices can be found for as low as $399. Flights from Seattle to Illinois on a Sunday will generally be more expensive and average around $513. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.
What is the cheapest time of day to depart on your flight to Illinois?
Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from Seattle to Illinois during this time can be as low as $289. Flights in the morning are often more expensive with an average ticket price of $467.
What is the cheapest Seattle/Tacoma Intl to Illinois flight route?
Fly from Seattle/Tacoma Intl to Chicago Midway for the best Seattle/Tacoma Intl - Illinois flight prices
How far in advance should I book a flight to Illinois?
You are more likely to see cheaper flights to Illinois from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $307 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Seattle for as low as $251 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to Illinois flights?
There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to Illinois 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 Seattle/Tacoma Intl to Illinois?
Hawaiian Airlines, United Airlines, and Southwest are the most popular carriers operating from Seattle/Tacoma Intl to Illinois
What airlines fly to Illinois?
Alaska Airlines, Delta and American Airlines are the top three most popular airlines that fly to Illinois from Seattle according to our data. Alaska Airlines is the first choice among our users, with 31% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 8 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.
How many flights depart from Seattle to Illinois on average per day?
The number of flights available between Seattle and Illinois is 83 per day as of June 2025. The most frequent departure time is 10:00AM, with 50% of daily flights leaving at noon.
How many flights depart from Seattle to Illinois on average per week?
As of June 2025, 581 flights take off from Seattle and land in Illinois each week. The most common flight departure day for this route is Mon, with 17% of weekly flights taking off on this day.
Cheap Seattle to Illinois flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Seattle to Illinois
When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Illinois?
Prices for flights from Seattle/Tacoma Intl Airport to Illinois are updated daily.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Illinois?
There are 8 operators available for flights from Seattle/Tacoma Intl Airport to Illinois as of June 2025.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to Illinois?
The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Illinois.
What documentation or ID do you need to fly to Illinois?
The necessary travel and health documents for your Illinois trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Seattle to Illinois?
Based on momondo bookings for flights between Seattle and Illinois, the leading plane model is Boeing 737-900 Passenger/BBJ3 (winglets), making up 18.28% of the total bookings. Other popular models include Boeing 737-800 with 14.93%, Boeing 737-800 Passenger/BBJ2 (winglets) with 11.86%, and Boeing 737 MAX 9 with 11.48%.
Best airlines flying from Seattle to Illinois
Compare and see reviews for airlines that fly from Seattle to Illinois with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $107 | Free Cancellation | Rating 6.3 8,065 reviews | |||
| PriceFrom $119 | Free Cancellation | Rating 7.8 2,507 reviews | |||
| PriceFrom $124 | Free Cancellation | Rating 8.0 7,964 reviews | |||
| PriceFrom $137 | Free Cancellation | Rating 5.9 3,301 reviews | |||
| PriceFrom $158 | Free Cancellation | Rating 7.4 8,810 reviews | |||
| PriceFrom $168 | Free Cancellation | Rating 8.0 10,000 reviews | |||
| PriceFrom $169 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $188 | Free Cancellation | Rating 8.0 4,280 reviews |
Why use momondo?
Why should I use momondo to find a flight deal from Seattle to Illinois?
momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to Illinois. Millions of users trust and use momondo every year so you are in good hands.
Can I find flights from Seattle to Illinois with flexible booking policies on momondo?
All flight searches from Seattle to Illinois on momondo can be filtered to show those which offer flexible booking policies.
How can momondo help me find flights from Seattle to Illinois?
Once all potential Seattle to Illinois flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.
I’m not ready to book a flight from Seattle to Illinois right now. Can momondo alert me if prices change?
Price alerts on flights to Illinois from Seattle are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.