Cheap flights from Washington to Southwest Illinois

View AU$137 flight on Wed, 27 Aug. 2025Opens in a new window

Popular airlines from Washington to Southwest Illinois

  • Jetstar

    Jetstar

  • Qantas Airways

    Qantas Airways

  • Virgin Australia

    Virgin Australia

  • Scoot

    Scoot

  • American Airlines

    American Airlines

  • Emirates

    Emirates

  • United

    United

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 35% on select hotels after you book a flight*
  • payments icon

    Earn twice

    Earn your airline miles on top of our rewards
    Sign in

Cheap Flights from Washington (WAS) to Southwest Illinois (STL)

Prices were available within the past 7 days for one-way flights and round trip tickets for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Sat, 6 Sep. - Sat, 13 Sep.
BWI
Baltimore
STL
St. Louis
AU$272 Return, found 3 days ago
AU$272
Return
found 3 days ago
Select American Airlines flight, departing Sat, 6 Sep. from Baltimore to St. Louis, returning Sat, 13 Sep., priced at AU$272 found 3 days ago
American Airlines
Sat, 6 Sep. - Sat, 13 Sep.
DCA
Washington
STL
St. Louis
AU$275 Return, found 3 days ago
AU$275
Return
found 3 days ago
Select American Airlines flight, departing Sat, 6 Sep. from Washington to St. Louis, returning Sat, 13 Sep., priced at AU$275 found 3 days ago
Delta
Sat, 6 Sep. - Sat, 13 Sep.
IAD
Washington
STL
St. Louis
AU$305 Return, found 3 days ago
AU$305
Return
found 3 days ago
Select Delta flight, departing Sat, 6 Sep. from Washington to St. Louis, returning Sat, 13 Sep., priced at AU$305 found 3 days ago
Delta
Sat, 6 Sep. - Sat, 13 Sep.
DCA
Washington
STL
St. Louis
AU$305 Return, found 3 days ago
AU$305
Return
found 3 days ago
Select Delta flight, departing Sat, 6 Sep. from Washington to St. Louis, returning Sat, 13 Sep., priced at AU$305 found 3 days ago
American Airlines
Sat, 6 Sep. - Sat, 13 Sep.
DCA
Washington
STL
St. Louis
AU$330 Return, found 3 days ago
AU$330
Return
found 3 days ago
Select American Airlines flight, departing Sat, 6 Sep. from Washington to St. Louis, returning Sat, 13 Sep., priced at AU$330 found 3 days ago
United
Sat, 6 Sep. - Sat, 13 Sep.
IAD
Washington
STL
St. Louis
AU$344 Return, found 3 days ago
AU$344
Return
found 3 days ago
Select United flight, departing Sat, 6 Sep. from Washington to St. Louis, returning Sat, 13 Sep., priced at AU$344 found 3 days ago
*Available to Expedia members.