$404 Cheap United flights St. Louis (STL) to Washington (IAD)

View $404 flight on Sat, Dec 27, 2025Opens in a new window

$404 Cheap United flights St. Louis (STL) to Washington (IAD)

Prices were available within the past 7 days and start at $404 for one-way flights and $348 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Tue, Dec 30 - Wed, Dec 31
STL
St. Louis
IAD
Washington
$348 Roundtrip, found 1 day ago
$348
Roundtrip
found 1 day ago
Select United flight, departing Tue, Dec 30 from St. Louis to Washington, returning Wed, Dec 31, priced at $348 found 1 day ago
United
Tue, Dec 30 - Wed, Dec 31
STL
St. Louis
IAD
Washington
$358 Roundtrip, found 1 day ago
$358
Roundtrip
found 1 day ago
Select United flight, departing Tue, Dec 30 from St. Louis to Washington, returning Wed, Dec 31, priced at $358 found 1 day ago
United
Tue, Dec 30 - Wed, Dec 31
STL
St. Louis
IAD
Washington
$368 Roundtrip, found 1 day ago
$368
Roundtrip
found 1 day ago
Select United flight, departing Tue, Dec 30 from St. Louis to Washington, returning Wed, Dec 31, priced at $368 found 1 day ago
United
Tue, Dec 30 - Wed, Dec 31
STL
St. Louis
IAD
Washington
$383 Roundtrip, found 1 day ago
$383
Roundtrip
found 1 day ago
Select United flight, departing Tue, Dec 30 from St. Louis to Washington, returning Wed, Dec 31, priced at $383 found 1 day ago
United
Tue, Dec 30 - Wed, Dec 31
STL
St. Louis
IAD
Washington
$393 Roundtrip, found 1 day ago
$393
Roundtrip
found 1 day ago
Select United flight, departing Tue, Dec 30 from St. Louis to Washington, returning Wed, Dec 31, priced at $393 found 1 day ago
United
Tue, Dec 30 - Wed, Dec 31
STL
St. Louis
IAD
Washington
$403 Roundtrip, found 1 day ago
$403
Roundtrip
found 1 day ago
Select United flight, departing Tue, Dec 30 from St. Louis to Washington, returning Wed, Dec 31, priced at $403 found 1 day ago

Find the cheapest month to fly from St. Louis (STL) to Washington (IAD)

December is typically the cheapest month to fly

From $134 - $704 per traveler.

Alternative airports near Washington

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

Select flight to Ronald Reagan Washington National DCA. Closest option available. Average driving time to city center is 8 minutes. Flights from $348
DCA
Ronald Reagan Washington National
Closest
Average driving time to city center8 min
Flights from $348
Flights from St. Louis (STL) to Washington (IAD)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Washington Dulles Intl.
Airlines serving
American Airlines, Delta, Frontier Airlines, United
Popular airline
United
Distance
1111 km
Average flight time
3 hours 10 mins