$52 Find Cheap Flights from Washington, D.C. to St. Charles

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Washington, D.C. to St. Charles departing on 1/21. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$128
Overall average: $349
Frontier
Wed 1/14Wed 1/21
BWI - STL • 1 stop
Cheapest non-stop
$261
Typical prices: $247-$445
American Airlines
Thu 1/1Mon 1/5
DCA - STL • Non-stop
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Flight Deals
Useful Info
Flight Deals

Cheap Flights from Washington, D.C. to St. Charles (WAS-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Washington, D.C. to St. Charles that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Washington, D.C. to St. Charles

Wed, Jan 14 - Wed, Jan 21
Frontier Logo
8:00 am - 10:34 pm
BWI
-
STL
15h 34m1 stop
Frontier Logo
5:42 pm - 4:42 pm
STL
-
BWI
22h 00m1 stop
$128Frontier
Thu, Feb 19 - Sun, Feb 22
Frontier Logo
9:11 pm - 7:50 am
BWI
-
STL
11h 39m1 stop
Frontier Logo
8:06 pm - 8:26 am
STL
-
BWI
11h 20m1 stop
$145Frontier
Fri, Jan 23 - Mon, Jan 26
Multiple Airlines Logo
4:44 pm - 11:33 pm
BWI
-
STL
7h 49m1 stop
Multiple Airlines Logo
5:42 pm - 11:47 pm
STL
-
BWI
29h 05m1 stop
$148Multiple Airlines
Fri, Feb 27 - Sun, Mar 1
Multiple Airlines Logo
4:30 pm - 10:33 pm
BWI
-
STL
7h 03m1 stop
Multiple Airlines Logo
8:45 am - 7:47 am
STL
-
BWI
22h 02m1 stop
$169Multiple Airlines
Wed, Jan 14 - Wed, Jan 21
Delta Logo
6:20 am - 11:05 am
IAD
-
STL
5h 45m1 stop
Delta Logo
6:00 am - 11:44 am
STL
-
IAD
4h 44m1 stop
$255Delta
Sat, Jan 17 - Sun, Jan 18
Southwest Logo
12:45 pm - 8:10 pm
DCA
-
STL
8h 25m2 stops
Southwest Logo
6:20 am - 3:25 pm
STL
-
DCA
8h 05m2 stops
$261Southwest
Thu, Jan 29 - Sat, Jan 31
American Airlines Logo
7:40 am - 9:24 am
DCA
-
STL
2h 44mnonstop
American Airlines Logo
6:00 am - 9:19 am
STL
-
DCA
2h 19mnonstop
$265American Airlines
Thu, Jan 1 - Mon, Jan 5
Southwest Logo
8:15 am - 9:35 am
DCA
-
STL
2h 20mnonstop
Southwest Logo
7:55 am - 12:50 pm
STL
-
DCA
3h 55m1 stop
$267Southwest
Thu, Jan 29 - Sat, Jan 31
American Airlines Logo
5:24 pm - 11:12 pm
DCA
-
STL
6h 48m1 stop
American Airlines Logo
6:00 am - 9:19 am
STL
-
DCA
2h 19mnonstop
$275American Airlines
Wed, Feb 4 - Thu, Feb 5
Delta Logo
6:00 pm - 11:37 pm
DCA
-
STL
6h 37m1 stop
Delta Logo
5:32 pm - 11:10 pm
STL
-
DCA
4h 38m1 stop
$285Delta
Useful Info

Good to know

Low seasonFebruary
Cheapest flight$52
Best time to beat the crowds but there is an average 11% increase in price.
Most popular time to fly and prices are also 10% lower on average.
Flight from Baltimore to St. Louis

When to book flights from Washington, D.C. to St. Charles

Are your dates flexible? Find out the best times to travel from Washington, D.C. to St. Charles based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Washington, D.C. to St. Charles

  • Which airports will I be using when flying from Washington, D.C. to St. Charles?

    When flying out of Washington, D.C. you’ll be using one of these airports: Washington, D.C. Reagan-National or Washington, D.C. Dulles Intl. St. Charles does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 7.2 mi away.

  • How long does a flight from Washington, D.C. to St. Charles take?

    Direct flights cover the 717 miles separating Washington, D.C. and St. Charles in about 2h 20m.

  • How many flights are there between Washington, D.C. and St. Charles?

    22 direct flights run between Washington, D.C. and St. Charles on a daily basis. On average, there are about 160 departures each week.

  • What’s the cheapest day of the week to fly between Washington, D.C. and St. Charles?

    Consider leaving on a Tuesday and avoid Sundays if you are looking for the best rates. For your return to Washington, D.C., you’ll find the best rates on Mondays and the most expensive ones on Sundays.

  • How does KAYAK find such low prices on flights from Washington, D.C. to St. Charles?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Washington, D.C. to St. Charles.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington, D.C. to St. Charles?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Charles from Washington, D.C. is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Washington, D.C. to St. Charles?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Charles with an airline and back to Washington, D.C. with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington, D.C. to St. Charles?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Charles from Washington, D.C. up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Washington, D.C. to St. Charles?

    In the last 72 hours, the cheapest one-way ticket between Washington, D.C. and St. Charles found on KAYAK was with Frontier for $58. Frontier offered a round-trip connection from $78 and Delta from $124.

Top tips for finding cheap flights from Washington, D.C. to St. Charles

  • There is no airport in St. Charles. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Washington, D.C. and St. Charles.
  • The cheapest flight from Washington, D.C. to St. Charles was found 63 days before departure, on average.
  • Book at least 3 weeks before departure in order to get a below-average price.
  • High season is considered to be November, December and January. The cheapest month to fly is August.

Reviews of the top 5 airlines serving Washington, D.C. to St. Charles

 
Need help choosing which airline to fly with from Washington, D.C. to St. Charles? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4252 reviews
7.5Entertainment
8.0Comfort
8.6Crew
8.1Boarding
7.0Food
Airline reviews

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

10.0 ExcellentAnonymous, Dec 2025
LAX - SFO
Read more Southwest reviews

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

Still a fan of open seating. Flight was on schedule and arrived on time. The 737 MAX is very comfortable.

Airline travel is always too cramped to really be pleasant, but the cabin crew on this flight did a pretty good job of making up for it by putting on some music during boarding and sprinkling a few funny remarks into the safety briefing and announcements, and just generally being friendly and helpful. It definitely reminded me of why I prefer the in-flight experience on Southwest!

No delays and arrived to destination 30 min early. Staff was super friendly.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

Had to get off plane from prior flight even though I had to reboard same plane to continue to my final destination.

Everything a cheap airline should be at normal airline rates.

Plane crashed into a bus or some other vehicle on the ground while pulling out of the gate. No injuries, but wing tip was damaged and returned to gate for “maintenance issues” and we departed 5 hours later because the plane went out of service and new plane was flown in from a nearby airport, Midway.

The food is terrible. The staff is wonderful. Comfort is good.

Left on time, a bit delayed due to headwinds most of the trip.

I fly Delta all the time, have Platinum Medallion status. But this route seems to have major problems with delays and seems to never leave on time! Have only taken it twice in the last two weeks, and each time it had delays of more than 1 hour... very disappointed!!!!

Good seats in Main cabin, excellent service and excellent landing

My flight was cancelled with no explanation after I had already cleared security. I was given 4 options to rebook, only one being non-stop like I had paid for. I grabbed it. It was 4 plus hours later and then took off even later. Biggest complaint is that I booked early and had an aisle seat. They gave me a "window" seat in front of the exit row, so the seat did not decline. I weigh all of 103 #s and it was tight for me! For what I paid, I feel I was kind of ripped off. I think they should have given me the empty comfort seat for the inconvenience. There was no apology nor any explanation as to why the flight was cancelled. My guess is it benefitted Delta in some way.

Very smooth, on-time, and pleasantly uneventful flight. The team at the gate and on board were professional and genuinely courteous. The pilot kept us well updated throughout, and both takeoff and landing were steady and enjoyable without any drama. Just a good, solid flight. Thank you! 💗

Staff was exceptional! Everyone was kind, professional and friendly making the trip very pleasant. Thank you!

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

We had a lot of really rough weather but that was not Delta's fault. Pilot was amazing.

First, Delta needs more flights to/from Miami. Second, a 1000pm leaving at 1230pm is unacceptable from their biggest airport world hub. Another aircraft could have been used such as the aircraft scheduled to be used in the morning for that exact same route. Yes, I did get me there but the lack of sleep the next day didn't help me enjoy my entire trip since I was busy with activities during the weekend. This can be and is expected from Spirit (going bankrupt) and Frontier (despite they're nickel and dimers). But from Delta's World Hub? That's totally unacceptable!

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

Starlink wifi on the Embraer E175 is an excellent experience. I was able to connect and work from IAD all the way to approach into BTV.

7 hours delayed due to operational issues on United’s end. Basically laziness.

Short flight but an "eager to help" crew made the journey more enjoyable!

During booking, I kept trying submitting my payment from the Mexican website and it didn't work. After I had the idea to change it to the Canadian website, it worked but I had to be charged the equivalent of 50 CAD more. I received the clear instruction that I would only be able to check-in at the airport and that it was impossible to select a seat 24 hours before departure, that I had to pay 144 CAD to do so, although not only was I able to check-in 24 hours before departure, but I could have selected my seats for free then. All in all, I almost threw $200 out the window due to misleading information. Besides, the app kept crashing, the information to get to the gate on the app was inaccurate, my gate was switched and I was only informed once in the air (luckily I had noticed the departure pannel), I was not addressed in my language beforehand and even if I tried I was immediately answered in English (which meant the crew understood but didn't want to answer accordingly), there was only one snack & beverage service on my medium haul flight and no beverage service on my short haul flight. To be fair, the planes were comfortable, the crew apart from the language issue was helpful, dynamic and engaging, the plane was clean and the directions were clear and direct. United has a lot of potential to be one of my favourite airlines, but the devil is in the details and a lot of them missed the target.

Better WiFi. I cannot understand that in 2025, United is so behind on a technology that is now a necessity and still painfully unreliable, slow and keeps disconnecting.

Great service on board. Boarding a bit slow due to process. Food was pretty average.

Very small cramped plane for an international flight. Everything else was good, but it was maybe the smallest comfort-wise I've ever been on for longer than 3-4 hours and the trip was 7.5

Flight was delayed 3 hours. No food and drink vouchers was provided. They offered a mini pretzel bag and water .

Staff was rude. Didn’t give water for 2 hours. Worst service

I got sick nothing contagious but distressing and the care I received by Kayla? Keighly the flight attendant will be memorable for ever. Thank You

We were told the flight was delayed 5 times, then it was moved to the next day.

Flight delay was communicated before leaving for airport which caused it to be a non-event. Great flight and crew!

The flight attendant, a black woman with curly hair who sat near Row 21, was wonderful and kind.

It took way too long to diagnose and solve the problem of a broken crew member cabin seat. Though compensation for the volunteer who left the flight was very kind.

We fly American Airlines quite a bit. And we always fly business class when traveling internationally. We were a bit disappointed with the comfort of this particular plane as well as the entertainment options.

The AA staff person who checked our bags was curt and almost rude. The FA also seemed unhappy doing her job. Overall it was like riding the school bus back in grade school.

They are still charging me after taking 466 and 833 for round trip from AR to to Bradley airport from 19 to 21. Then poor experience. Am hurt and I will say it on social media. Please stay away from this airline. I see in my bank account they are still taking 644. Am trying to stop it. I used to fly United airlines and I suggest that if you don't want extra charges and good service you go back there. American airlines delayed my flight again and I was late for my meeting, no recompensation but charging me over and over.

They changed our Gate 5 times, and concourse twice. Changed our seats twice.

Pitch was very small. Knees were on the seat back in front of me.

Not clean and was told I would get a great seat and it was not great at all

Flight got delayed for 5 hours no good explanation was offered ;(

Horrible. I would never fly Frontier again. The booking process is tricky at best, but fraudulent in my opinion. Frontier customer service did nothing to rectify my purchase -- I ended up paying more than double what I could have gotten from other airlines and nearly triple what I thought I was buying from Frontier. Their booking practices are unfair to the consumer.

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

Better than expected. Staff were friendly and nice on both flights.

There was no one at the counter to assist with our check in. The app didn’t work, so I arrived at the airport with time to check in and I couldn’t because no employees were there. When I finally got someone on the phone, it was inside the 60min rule and they said I could no longer check in and they could sell me another ticket. We had to scramble and pay an additional $800 for tickets and THEN AFTER (about 60 min from my original convo with customer service and 10min after original departure time) I had boarded my new flight, there was email saying my original flight from Frontier was delayed and leaving 2hr 50min later, but I STILL wouldn’t have been able to check in. Which means customer service should have been able to see it and let me check in because I was well within my check in time. When I call Frontier, they hang up on me. So their app didn’t work and they employees left and they take zero responsibility or assistance with their “customer service”

Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.

No fault of Frontier staff: plane was very late, reached Orlando at 1 am, took a while to get luggage. Weather, gov financial shutdown impact on TSA, air controllers seemed to have multiple flights backed up. Frontier staff seemed to cope as gracefully as possible. It did reassure me that I and my new hip could adapt to travel challenges. Food/entertainment were irrelevant to my trip.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

Everything you need to know for your flight from Washington, D.C. to St. Charles

Complete your trip to St. Charles with a hotel stay or car rental