Flights from St. Louis to Union

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Cheapest flights from St. Louis

These prices were available within the past 7 days. Prices quoted are per person, round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$167 Roundtrip, found 1 day ago
$167
Roundtrip
found 1 day ago
Select American Airlines flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $167 found 1 day ago
American Airlines
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$168 Roundtrip, found 1 day ago
$168
Roundtrip
found 1 day ago
Select American Airlines flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $168 found 1 day ago
Delta
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$176 Roundtrip, found 1 day ago
$176
Roundtrip
found 1 day ago
Select Delta flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $176 found 1 day ago
Delta
Mon, Jun 30 - Wed, Jul 9
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$177 Roundtrip, found 7 hours ago
$177
Roundtrip
found 7 hours ago
Select Delta flight, departing Mon, Jun 30 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Wed, Jul 9, priced at $177 found 7 hours ago
Delta
Sun, Jun 29 - Wed, Jul 9
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$183 Roundtrip, found 7 hours ago
$183
Roundtrip
found 7 hours ago
Select Delta flight, departing Sun, Jun 29 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Wed, Jul 9, priced at $183 found 7 hours ago
Delta
Fri, Jun 13 - Tue, Jun 17
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$189 Roundtrip, found 3 days ago
$189
Roundtrip
found 3 days ago
Select Delta flight, departing Fri, Jun 13 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Tue, Jun 17, priced at $189 found 3 days ago
United
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$196 Roundtrip, found 1 day ago
$196
Roundtrip
found 1 day ago
Select United flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $196 found 1 day ago
Delta
Wed, Jun 11 - Thu, Jun 12
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$197 Roundtrip, found 1 day ago
$197
Roundtrip
found 1 day ago
Select Delta flight, departing Wed, Jun 11 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Thu, Jun 12, priced at $197 found 1 day ago
Delta
Tue, Jun 10 - Mon, Jun 16
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$198 Roundtrip, found 1 day ago
$198
Roundtrip
found 1 day ago
Select Delta flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Mon, Jun 16, priced at $198 found 1 day ago
Delta
Thu, Jul 3 - Wed, Jul 9
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$208 Roundtrip, found 7 hours ago
$208
Roundtrip
found 7 hours ago
Select Delta flight, departing Thu, Jul 3 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Wed, Jul 9, priced at $208 found 7 hours ago
American Airlines
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$209 Roundtrip, found 1 day ago
$209
Roundtrip
found 1 day ago
Select American Airlines flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $209 found 1 day ago
American Airlines
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$212 Roundtrip, found 1 day ago
$212
Roundtrip
found 1 day ago
Select American Airlines flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $212 found 1 day ago
American Airlines
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$213 Roundtrip, found 1 day ago
$213
Roundtrip
found 1 day ago
Select American Airlines flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $213 found 1 day ago
Delta
Fri, Jun 13 - Mon, Jun 16
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$214 Roundtrip, found 3 days ago
$214
Roundtrip
found 3 days ago
Select Delta flight, departing Fri, Jun 13 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Mon, Jun 16, priced at $214 found 3 days ago
Delta
Wed, Jun 11 - Mon, Jun 16
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$218 Roundtrip, found 1 day ago
$218
Roundtrip
found 1 day ago
Select Delta flight, departing Wed, Jun 11 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Mon, Jun 16, priced at $218 found 1 day ago
Delta
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$221 Roundtrip, found 1 day ago
$221
Roundtrip
found 1 day ago
Select Delta flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $221 found 1 day ago
Frontier Airlines
Sat, Jun 7 - Tue, Jun 10
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$229 Roundtrip, found 1 day ago
$229
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Sat, Jun 7 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Tue, Jun 10, priced at $229 found 1 day ago
United
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$268 Roundtrip, found 1 day ago
$268
Roundtrip
found 1 day ago
Select United flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $268 found 1 day ago
Hawaiian Airlines
Thu, Jun 12 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$269 Roundtrip, found 1 day ago
$269
Roundtrip
found 1 day ago
Select Hawaiian Airlines flight, departing Thu, Jun 12 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $269 found 1 day ago
Alaska Airlines
Tue, Jun 10 - Fri, Jun 13
STL
Lambert-St. Louis Intl.
SEA
Seattle - Tacoma Intl.
$333 Roundtrip, found 1 day ago
$333
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Tue, Jun 10 from Lambert-St. Louis Intl. to Seattle - Tacoma Intl., returning Fri, Jun 13, priced at $333 found 1 day ago