Flights from Chicago to Union

Cheapest flights from Chicago

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.

Tue, Jul 22 - Wed, Jul 23

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$169 Roundtrip, found 3 days ago

$169

Roundtrip

found 3 days ago

Select Alaska Airlines flight, departing Tue, Jul 22 from O'Hare Intl. to Seattle - Tacoma Intl., returning Wed, Jul 23, priced at $169 found 3 days ago

Thu, Jul 17 - Wed, Jul 23

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$199 Roundtrip, found 3 days ago

$199

Roundtrip

found 3 days ago

Select Alaska Airlines flight, departing Thu, Jul 17 from O'Hare Intl. to Seattle - Tacoma Intl., returning Wed, Jul 23, priced at $199 found 3 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$199 Roundtrip, found 6 days ago

$199

Roundtrip

found 6 days ago

Select United flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $199 found 6 days ago

Fri, Jul 18 - Tue, Jul 22

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$199 Roundtrip, found 3 days ago

$199

Roundtrip

found 3 days ago

Select Delta flight, departing Fri, Jul 18 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 22, priced at $199 found 3 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$203 Roundtrip, found 6 days ago

$203

Roundtrip

found 6 days ago

Select American Airlines flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $203 found 6 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$205 Roundtrip, found 6 days ago

$205

Roundtrip

found 6 days ago

Select American Airlines flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $205 found 6 days ago

Fri, Aug 1 - Tue, Aug 12

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$209 Roundtrip, found 5 days ago

$209

Roundtrip

found 5 days ago

Select Alaska Airlines flight, departing Fri, Aug 1 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Aug 12, priced at $209 found 5 days ago

Mon, Jul 21 - Wed, Jul 23

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$209 Roundtrip, found 3 days ago

$209

Roundtrip

found 3 days ago

Select Hawaiian Airlines flight, departing Mon, Jul 21 from O'Hare Intl. to Seattle - Tacoma Intl., returning Wed, Jul 23, priced at $209 found 3 days ago

Thu, Jul 17 - Thu, Jul 24

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$229 Roundtrip, found 3 days ago

$229

Roundtrip

found 3 days ago

Select Hawaiian Airlines flight, departing Thu, Jul 17 from O'Hare Intl. to Seattle - Tacoma Intl., returning Thu, Jul 24, priced at $229 found 3 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$233 Roundtrip, found 6 days ago

$233

Roundtrip

found 6 days ago

Select American Airlines flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $233 found 6 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$235 Roundtrip, found 6 days ago

$235

Roundtrip

found 6 days ago

Select American Airlines flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $235 found 6 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$237 Roundtrip, found 6 days ago

$237

Roundtrip

found 6 days ago

Select American Airlines flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $237 found 6 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$238 Roundtrip, found 6 days ago

$238

Roundtrip

found 6 days ago

Select United flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $238 found 6 days ago

Thu, Jul 17 - Mon, Jul 21

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$239 Roundtrip, found 3 days ago

$239

Roundtrip

found 3 days ago

Select Hawaiian Airlines flight, departing Thu, Jul 17 from O'Hare Intl. to Seattle - Tacoma Intl., returning Mon, Jul 21, priced at $239 found 3 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$242 Roundtrip, found 6 days ago

$242

Roundtrip

found 6 days ago

Select American Airlines flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $242 found 6 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$243 Roundtrip, found 6 days ago

$243

Roundtrip

found 6 days ago

Select United flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $243 found 6 days ago

Fri, Jul 11 - Tue, Jul 15

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$244 Roundtrip, found 6 days ago

$244

Roundtrip

found 6 days ago

Select United flight, departing Fri, Jul 11 from O'Hare Intl. to Seattle - Tacoma Intl., returning Tue, Jul 15, priced at $244 found 6 days ago

Sat, Jul 19 - Sat, Jul 26

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$248 Roundtrip, found 3 days ago

$248

Roundtrip

found 3 days ago

Select Frontier Airlines flight, departing Sat, Jul 19 from O'Hare Intl. to Seattle - Tacoma Intl., returning Sat, Jul 26, priced at $248 found 3 days ago

Sun, Jun 15 - Thu, Jun 19

MDW

Midway Intl.

SEA

Seattle - Tacoma Intl.

$259 Roundtrip, found 5 days ago

$259

Roundtrip

found 5 days ago

Select Frontier Airlines flight, departing Sun, Jun 15 from Midway Intl. to Seattle - Tacoma Intl., returning Thu, Jun 19, priced at $259 found 5 days ago

Sun, Jul 20 - Mon, Jul 21

ORD

O'Hare Intl.

SEA

Seattle - Tacoma Intl.

$281 Roundtrip, found 3 days ago

$281

Roundtrip

found 3 days ago

Select Spirit Airlines flight, departing Sun, Jul 20 from O'Hare Intl. to Seattle - Tacoma Intl., returning Mon, Jul 21, priced at $281 found 3 days ago