$28 Cheap Flights to Union, MO

View $28 flight on Wed, Jun 17, 2026Opens in a new window

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Popular airlines to Union

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How much is the cheapest flight to Union?

Prices were available within the past 7 days and start at $28 for one-way flights and $63 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Tue, May 26 - Thu, May 28
DEN
Denver
STL
St. Louis
$63 Roundtrip, found 1 hour ago
$63
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Tue, May 26 from Denver to St. Louis, returning Thu, May 28, priced at $63 found 1 hour ago
United
Tue, Jun 30 - Wed, Jul 1
DEN
Denver
STL
St. Louis
$201 Roundtrip, found 3 hours ago
$201
Roundtrip
found 3 hours ago
Select United flight, departing Tue, Jun 30 from Denver to St. Louis, returning Wed, Jul 1, priced at $201 found 3 hours ago
Southwest Airlines
Tue, Jun 30 - Wed, Jul 1
DEN
Denver
STL
St. Louis
$201 Roundtrip, found 3 hours ago
$201
Roundtrip
found 3 hours ago
Select Southwest Airlines flight, departing Tue, Jun 30 from Denver to St. Louis, returning Wed, Jul 1, priced at $201 found 3 hours ago
Delta
Tue, Jun 30 - Wed, Jul 1
DEN
Denver
STL
St. Louis
$221 Roundtrip, found 3 hours ago
$221
Roundtrip
found 3 hours ago
Select Delta flight, departing Tue, Jun 30 from Denver to St. Louis, returning Wed, Jul 1, priced at $221 found 3 hours ago
Alaska Airlines
Wed, Jun 3 - Sat, Jun 6
SEA
Seattle
STL
St. Louis
$297 Roundtrip, just found
$297
Roundtrip
just found
Select Alaska Airlines flight, departing Wed, Jun 3 from Seattle to St. Louis, returning Sat, Jun 6, priced at $297 just found

Frequently asked questions

What month is the cheapest to fly to Union?
Plan your trip for May if you want to get a deal on your fare. It's the cheapest month to fly to Union. If possible, avoid traveling during peak periods such as public holidays or school breaks.
Which US cities have the cheapest flights to Union?
Get cheap flights to Union from Chicago, Dallas and Denver. These cities generally offer the best fares to this popular destination. But bear in mind that stopovers, holiday periods and demand will also have an influence on rates, so remain flexible and book when you spot a bargain.
Which US cities fly direct to Union?
There are 55 US cities you're able to fly to Union directly from. Explore your options by using the "Direct flights only" filter on Expedia and find the best departure point for your trip. Here are several of the leading cities to leave from:

  • Chicago
  • Dallas
  • Denver
  • New York
  • Atlanta

How to find a cheap flight to Union?
To secure cheap flights to Union, book in advance or travel during the off-peak months of January and August. Want an insider tip? Take off on a Thursday and save around 16% on average compared to traveling on a Sunday.* Opt to receive price alerts on the Expedia app and you'll get notified as soon as your fares go down.*Best day of the week to book, depart and ideal booking window recommendations based on average round-trip ticket prices for January through August 2023, sourced from Airline Reporting Corporation's (ARC) global airline sales database. Percentages noted are averages.
How to get a cheap last-minute flight to Union?
Although booking in advance is usually the easiest way to save cash, don't panic if your Union trip is last minute. You can still find cheap flights to Union, especially if your plans have some flexibility. Try switching up your trip dates, exploring different ticket options or departing from another hub.
How far in advance should I book a flight to Union?
Find the travel dates you want and a fare you'll love by booking your domestic flight to Union up to 28 days in advance. Search for tickets between two and four months ahead if you're traveling to Union from an international destination.**Best day of the week to book, depart and ideal booking window recommendations based on average round-trip ticket prices for January through August 2023, sourced from Airline Reporting Corporation's (ARC) global airline sales database. Percentages noted are averages.
Which day of the week is the cheapest day to buy a plane ticket to Union?
You can usually get cheap flights to Union on a Sunday. You'll save around 8% on average compared to those who book on a Friday, which is typically the most expensive day for tickets.**Best day of the week to book, depart and ideal booking window recommendations based on average round-trip ticket prices for January through August 2023, sourced from Airline Reporting Corporation's (ARC) global airline sales database. Percentages noted are averages.
Which airlines fly to Union?
There are 10 airlines that connect Union with 33 airports globally. The chief entry point to this city is Lambert-St. Louis Intl. Airport (STL). Fly with any of these leading airlines to Union:

  • Delta Air Lines
  • American Airlines
  • United Airlines
  • Southern Airways Express

Where do you fly into Union?
If you're flying to Union, the main hub to arrive at is Lambert-St. Louis Intl. Airport (STL). You could also fly to Union via Spirit of St. Louis Airport (SUS).
How far is the airport from central Union?
If you're touching down at Lambert-St. Louis Intl. Airport (STL), you'll be about 40 mi northeast of the center of Union.
Can I save money by booking a Union trip package?
You could possibly save hundreds of dollars if you lock in an Union flight and hotel package deal on Expedia. And you'll make life easier by having all your travel plans in one place. Try bundling your hotel and flight with extras such as activities and car rentals for your own customized Union vacation.
Can I change or cancel my flight to Union?
It's usually possible to change or cancel your flight to Union. Many airlines allow you to cancel flights for free within 24 hours of making your booking. However, some flights are non-refundable, and airlines may offer you a credit toward future flights in place of a direct refund. To find cheap flights to Union with flexible change policies, select "Changes included" or "No cancel fee" during your search. Need more information? Head to our Customer Service Portal.

*Flight schedules are subject to change.

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Travel information

Destination airport
Lambert-St. Louis Intl.
Destination airport IATA code
STL
Destination city name
St. Louis
Roundtrip price
$63

Trending flights to Union

Prices were available within the past 7 days and start at $28 for one-way flights and $63 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Tue, May 26 - Thu, May 28
DEN
Denver
STL
St. Louis
$63 Roundtrip, found 1 hour ago
$63
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Tue, May 26 from Denver to St. Louis, returning Thu, May 28, priced at $63 found 1 hour ago

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