$133 Cheap flight deals from Phoenix (PHX) to Union (STL)

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This Weekend's Flight Deals from Phoenix to Union

This weekend's flight prices found within the past 7 days, for the period specified. Prices and availability are subject to change. Additional terms apply.

Sat, Jun 6 - Sat, Jun 13
PHX
Sky Harbor Intl.
STL
Lambert-St. Louis Intl.
$333 Roundtrip, found 22 hours ago
$333
Roundtrip
found 22 hours ago
Select Frontier Airlines flight, departing Sat, Jun 6 from Sky Harbor Intl. to Lambert-St. Louis Intl., returning Sat, Jun 13, priced at $333 found 22 hours ago

Airfares from $133 One Way, $220 Round Trip from Phoenix to Union

Prices starting at $220 for return flights and $133 for one-way flights to Union were the cheapest prices found within the past 7 days, for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, Aug 4 - Thu, Aug 6
PHX
Phoenix
STL
St. Louis
$220 Roundtrip, found 2 days ago
$220
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Tue, Aug 4 from Phoenix to St. Louis, returning Thu, Aug 6, priced at $220 found 2 days ago
Tue, Aug 4 - Thu, Aug 6
PHX
Phoenix
STL
St. Louis
$245 Roundtrip, found 2 days ago
$245
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Tue, Aug 4 from Phoenix to St. Louis, returning Thu, Aug 6, priced at $245 found 2 days ago
Tue, Aug 4 - Thu, Aug 6
PHX
Phoenix
STL
St. Louis
$252 Roundtrip, found 2 days ago
$252
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Tue, Aug 4 from Phoenix to St. Louis, returning Thu, Aug 6, priced at $252 found 2 days ago
Tue, Jul 14 - Tue, Jul 28
PHX
Phoenix
STL
St. Louis
$262 Roundtrip, found 23 hours ago
$262
Roundtrip
found 23 hours ago
Select Frontier Airlines flight, departing Tue, Jul 14 from Phoenix to St. Louis, returning Tue, Jul 28, priced at $262 found 23 hours ago
Wed, Jul 1 - Wed, Jul 8
PHX
Phoenix
STL
St. Louis
$263 Roundtrip, found 5 hours ago
$263
Roundtrip
found 5 hours ago
Select Frontier Airlines flight, departing Wed, Jul 1 from Phoenix to St. Louis, returning Wed, Jul 8, priced at $263 found 5 hours ago

Union economy flight packages

Price found within the past 48 hours. Click for updated prices.
The Wildwood Hotel
3.5-star property

The Wildwood Hotel

9.2/10 Wonderful! (1,650 reviews)

Jul 25 - Jul 27

2 night stay

Phoenix (PHX) to St. Louis (STL)

Frontier Airlines • Non-stop roundtrip • Coach
Price was $616, price is now $430 per person
$430
per person
found 1 day ago
Hotel was clean but honestly, outdated. Staff was great. The continental breakfast was fine. Biggest issue was the shower. There was next to no water pressure no matter the time of day. The mattress also felt cheap. I’m not a picky person and overall, I would stay again. Just maybe not in an upgraded room. I don’t feel like it was worth it.

Reviewed on Feb 24, 2026

The Royal Sonesta Chase Park Plaza St. Louis
4.5-star property

The Royal Sonesta Chase Park Plaza St. Louis

9/10 Wonderful! (1,005 reviews)

Jul 3 - Jul 6

3 night stay

Phoenix (PHX) to St. Louis (STL)

American Airlines • Coach

St. Louis (STL) to Phoenix (PHX)

Frontier Airlines • Coach
Price was $830, price is now $712 per person
$712
per person
found 16 hours ago
Spotless room and a beautiful property.

Reviewed on Jan 12, 2026

21C Museum Hotel St Louis
4.5-star property

21C Museum Hotel St Louis

9/10 Wonderful! (1,854 reviews)

Jul 25 - Jul 27

2 night stay

Phoenix (PHX) to St. Louis (STL)

Frontier Airlines • Non-stop roundtrip • Coach
Price was $709, price is now $597 per person
$597
per person
found 1 day ago
Gorgeous, clean, unique, and within walking distance of everything fun! Valets were so helpful and friendly, right off the bat. They set an excellent first impression. The hotel alone provided a fantastic experience with the art exhibit and the main floor entertainment options. The gym area was the best we have ever seen at a hotel. We were so pleased with our stay and the affordability of it all! We can’t wait to book again.

Reviewed on Jun 3, 2026

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More About Flying To Union from Phoenix

Route Information for Flights from Phoenix to Union

Origin Airport IATA Code
PHX
Destination Airport IATA Code
STL
Distance
Direct Flight Airlines
Earliest Flight Arrival
Latest Flight Arrival

Phoenix to Union

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Orbitz looks for the best deals on Phoenix to Union flights for you. Mix and match airlines for your departing and return flights to fit your travel schedule and budget.

Fare, taxes & fees: Fares include all taxes and fees, except baggage fees. Rates shown reflect fares found by other Orbitz users over the past 7 days. Due to rapidly changing airline prices & seat availability, these fares may no longer be available.

Refunds/changes/cancellations: Itinerary changes, if permitted for the fare, will have a $30 service fee charged by Orbitz. Additional airline charges may apply.

Other conditions: Schedules, fares and rules are subject to change without notice. Seats are limited and may not be available on all flights/dates or in all markets. Lower fares may be available. Fares will not be honored retroactively or in exchange for any wholly/partially unused ticket. Tickets are non-transferable and non-refundable. Fare rules are provided for the selected itinerary before booking.