$51+ Cheap flights from St. Louis (STL) to Dulles Intl (IAD)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/7. Fares are subject to change and may not be available on all flights or dates of travel.
STL — IAD
Nov 5 — Nov 121
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Dulles Intl with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from St. Louis to Dulles Intl
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One-way
Cheapest flights from St. Louis to Dulles IntlExplore the most affordable flight options available from St. Louis to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 6, 2026.
Explore the most affordable flight options available from St. Louis to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 6, 2026.
This Mytrip deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:44 pm -
2 stops14h 37m
Sun 11/89:06 pm -
2 stops27h 10m
Deal found 10/5![Frontier logo]()
$251
This Kiwi.com deal was found by Cheapflights users on 10/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/266:35 pm -
1 stop21h 37m
Thu 10/299:06 pm -
2 stops15h 13m
Deal found 10/2![Frontier logo]()
$255
This Delta deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/147:13 am -
1 stop5h 41m
Thu 11/198:05 am -
1 stop6h 18m
Deal found 10/1![Delta logo]()
$257
This Kissandfly.com deal was found by Cheapflights users on 10/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/54:26 pm -
2 stops23h 46m
Mon 11/97:32 am -
1 stop11h 10m
Deal found 10/3![Frontier logo]()
$258
This Mytrip deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/294:26 pm -
2 stops30h 17m
Mon 11/27:40 am -
1 stop11h 00m
Deal found 10/1![Frontier logo]()
$261
This Mytrip deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/144:26 pm -
2 stops23h 46m
Thu 11/197:32 am -
1 stop12h 07m
Deal found 10/1![Frontier logo]()
$263
This Frontier deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:35 pm -
1 stop4h 46m
Wed 10/288:05 am -
1 stop10h 35m
Deal found 10/4![Frontier logo]()
$265
This Mytrip deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/304:26 pm -
2 stops30h 17m
Mon 11/211:16 am -
1 stop13h 00m
Deal found 10/1![Frontier logo]()
$268
Best flights from St. Louis to Dulles IntlDiscover carefully curated flight deals from St. Louis to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 6, 2026.
Discover carefully curated flight deals from St. Louis to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 6, 2026.
This Delta deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:00 pm -
1 stop4h 21m
Tue 11/176:00 am -
1 stop6h 15m
Deal found 10/1![Delta logo]()
$257
This United Airlines deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/66:00 am -
1 stop4h 52m
Thu 11/128:23 am -
1 stop4h 47m
Deal found 10/1![United Airlines logo]()
$286
This Delta deal was found by Cheapflights users on 10/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/25:38 pm -
1 stop6h 04m
Sat 11/712:20 pm -
1 stop4h 17m
Deal found 10/3![Delta logo]()
$275
This United Airlines deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/148:00 am -
Nonstop2h 10m
Thu 11/198:40 am -
Nonstop2h 32m
Deal found 10/1![United Airlines logo]()
$301
This Delta deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/56:47 am -
1 stop3h 47m
Mon 11/97:37 pm -
1 stop5h 19m
Deal found 10/1![Delta logo]()
$298
This United Airlines deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:30 am -
1 stop6h 08m
Thu 12/178:32 am -
Nonstop2h 33m
Deal found 10/1![United Airlines logo]()
$355
This United Airlines deal was found by Cheapflights users on 10/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/301:00 pm -
Nonstop2h 09m
Fri 11/65:29 pm -
1 stop5h 11m
Deal found 10/2![United Airlines logo]()
$357
This Delta deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/1212:36 pm -
1 stop6h 35m
Sun 12/136:00 am -
1 stop6h 29m
Deal found 10/4![Delta logo]()
$363
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/68:00 am -
Nonstop2h 10m
Sat 11/76:10 am -
1 stop5h 34m
Deal found 10/5![United Airlines logo]()
$357
This Delta deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/3010:35 am -
1 stop5h 07m
Sun 11/16:00 am -
1 stop5h 51m
Deal found 10/4![Delta logo]()
$387
This United Airlines deal was found by Cheapflights users on 10/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/231:00 pm -
Nonstop2h 06m
Sun 3/288:20 am -
Nonstop2h 28m
Deal found 10/6![United Airlines logo]()
$398
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/87:00 am -
1 stop5h 14m
Thu 3/118:20 am -
Nonstop2h 28m
Deal found 10/5![United Airlines logo]()
$405
Last-minute flights from St. Louis to Dulles IntlDiscover last-minute flight deals from St. Louis to Dulles Intl. Data last updated October 6, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Dulles Intl. Data last updated October 6, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 10/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:35 pm -
1 stop4h 46m
Wed 10/288:05 am -
1 stop10h 35m
Deal found 10/4![Frontier logo]()
$265
This Kiwi.com deal was found by Cheapflights users on 10/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/266:35 pm -
1 stop21h 37m
Thu 10/299:06 pm -
2 stops15h 13m
Deal found 10/2![Frontier logo]()
$255
This Mytrip deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/294:26 pm -
2 stops30h 17m
Mon 11/27:40 am -
1 stop11h 00m
Deal found 10/1![Frontier logo]()
$261
This Mytrip deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/304:26 pm -
2 stops30h 17m
Mon 11/211:16 am -
1 stop13h 00m
Deal found 10/1![Frontier logo]()
$268
This Mytrip deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:44 pm -
2 stops14h 37m
Sun 11/89:06 pm -
2 stops27h 10m
Deal found 10/5![Frontier logo]()
$251
This Kissandfly.com deal was found by Cheapflights users on 10/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/54:26 pm -
2 stops23h 46m
Mon 11/97:32 am -
1 stop11h 10m
Deal found 10/3![Frontier logo]()
$258
This Delta deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/147:13 am -
1 stop5h 41m
Thu 11/198:05 am -
1 stop6h 18m
Deal found 10/1![Delta logo]()
$257
This Mytrip deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/144:26 pm -
2 stops23h 46m
Thu 11/197:32 am -
1 stop12h 07m
Deal found 10/1![Frontier logo]()
$263
One-way flights from St. Louis to Dulles IntlSearch for one-way flight options from St. Louis to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated October 6, 2026.
Search for one-way flight options from St. Louis to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated October 6, 2026.
This Trip.com deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/712:02 pm -
1 stop22h 09m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/1![Frontier logo]()
$51
This Kiwi.com deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/136:34 pm -
1 stop21h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$59
This Kiwi.com deal was found by Cheapflights users on 10/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/412:02 pm -
1 stop25h 47m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/2![Frontier logo]()
$63
This Kiwi.com deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/116:34 pm -
1 stop21h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$69
This Kiwi.com deal was found by Cheapflights users on 10/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/306:44 pm -
1 stop21h 28m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/2![Frontier logo]()
$71
This Kiwi.com deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/197:24 pm -
1 stop15h 50m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$72
This Cheapflightsfares deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/215:15 pm -
1 stop10h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/1![Frontier logo]()
$99
This Mytrip deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/54:26 pm -
1 stop16h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![Frontier logo]()
$102
This Jetabroad deal was found by Cheapflights users on 10/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Jetabroad is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/56:13 pm -
1 stop26h 16m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/1![Frontier logo]()
$107
This United Airlines deal was found by Cheapflights users on 10/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/186:00 am -
1 stop6h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/5![United Airlines logo]()
$110
This Mytrip deal was found by Cheapflights users on 10/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:44 pm -
2 stops14h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/2![Frontier logo]()
$112
Find flight deals from St. Louis to Dulles Intl
Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Dulles Intl (IAD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated October 6, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $251 (Mytrip) |
One-way from | $51 (Trip.com) |
Popular in | September |
Cheapest in | February |
Average price | $412 |
Good round-trip deal | $643 or less |
Good one-way deal | $281 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Dulles Intl that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated October 6, 2026.
Use the filters below to find and compare flights from St. Louis to Washington, D.C. Dulles Intl Airport that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Sat 11/21
5:15 pm-5:10 am
1 stop10h 55m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$99
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Thu 12/3
7:18 pm-12:41 am
1 stop4h 23m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$138
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Thu 11/5
6:47 am-11:34 am
1 stop3h 47m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$138
Quickest round-trip
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Sat 12/5
8:30 am-11:35 am
Nonstop2h 05m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$146
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Sat 11/14
1:00 pm-4:09 pm
Nonstop2h 09m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$155
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Fri 1/1
10:45 am-5:22 pm
1 stop5h 37m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$158
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Sat 10/31
8:00 am-11:10 am
Nonstop2h 10m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$174
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Tue 11/3
8:00 am-11:10 am
Nonstop2h 10m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$174
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Tue 11/24
1:00 pm-4:09 pm
Nonstop2h 09m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$190
St. LouisWashington, D.C.
STL Lambert-St Louis - IAD Washington, D.C. Dulles Intl
STLIAD
Lambert-St Louis
Sat 12/5
7:27 am-6:44 pm
2 stops10h 17m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$213
Showing 1-10 of 24 resultsSorted by cheapest first
Compare providers for flights from St. Louis to Dulles Intl
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Dulles Intl in October.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star |
- Most accurate provider: When it comes to deals on St. Louis-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on St. Louis-Washington, D.C. Dulles Intl Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Washington, D.C. Dulles Intl Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from St. Louis to Dulles Intl
Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from St. Louis with our price prediction graph.
STL-IAD
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from St. Louis to Washington, D.C. Dulles Intl Airport
Prices
Airlines
What is the cheapest month to book a flight from St. Louis to Washington, D.C. Dulles Intl Airport?
Currently, February is the cheapest month in which you can book a flight from St. Louis to Washington, D.C. Dulles Intl Airport (average of $170). Flying from St. Louis to Washington, D.C. Dulles Intl Airport in September is currently the most expensive (average of $531). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from STL to IAD?
Find hourly flight availability from St. Louis to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 6, 2026.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from St. Louis to Washington, D.C. Dulles Intl Airport as you normally would.
The best insider tips for St. Louis to Washington, D.C. Dulles Intl Airport flights
AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Washington, D.C. Dulles Intl Airport trip
Our travel experts
Reviews of airlines servicing Dulles Intl
Get insights into the airlines that provide service to Dulles Intl. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Dulles Intl. Reviews last updated October 6, 2026.
Peruse reviews from past customers who have flown with Delta,United Airlines, andAmerican Airlines from St. Louis to Washington, D.C. Dulles Intl Airport to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Comfort
7.8
Food
7.2
Overall
7.8
Crew
8.5
Entertainment
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Boarding
8.1
Comfort
7.8
Food
7.2
Overall
7.8
Crew
8.5
Entertainment
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Boarding
8.1
Comfort
7.8
Food
7.2
Overall
7.8
Crew
8.5
Entertainment
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Boarding
8.1
Comfort
7.8
Food
7.2
Overall
7.8
Crew
8.5
Entertainment
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Boarding
8.1
Comfort
7.8
Food
7.2
Overall
7.8
Crew
8.5
Entertainment
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Dulles Intl. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Washington, D.C. Dulles Intl Airport?
Book flights to Washington, D.C. Dulles Intl Airport if you plan to visit one of these locationsAlexandria
Arlington
Woodbridge
Chantilly
Owings Mills
Lanham
Herndon
Tysons
Reston
Hyattsville
Rockville
Springfield
Fredericksburg
Falls Church
Sterling
Laurel
Oxon Hill
Towson
Clinton
Hunt Valley
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Other flights to Dulles Intl
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St. Louis and Dulles Intl flights
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Top 4 airlines flying from St. Louis to Dulles Intl
Discover the top 4 airlines that operate flights from St. Louis to Dulles Intl. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated October 6, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$90 | Average$201 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$203 | Average$364 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$257 | Average$325 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$264 | Average$469 | FlexibilityNo cancel fee | On-time69% |