$273 Cheap Flights from Casper (CPR) to Sidney (SDY)

View $273 flight on Fri, Oct 31, 2025Opens in a new window

Popular airlines from Casper, WY (CPR-Natrona County Intl.) to Sidney, MT (SDY-Sidney-Richland Municipal)

Cheap Flights from Casper to Sidney (CPR-SDY)

Prices were available within the past 7 days and start at $273 for one-way flights and $534 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Wed, Oct 29 - Sat, Nov 15
CPR
Casper
SDY
Sidney
$534 Roundtrip, found 4 days ago
$534
Roundtrip
found 4 days ago
Select United flight, departing Wed, Oct 29 from Casper to Sidney, returning Sat, Nov 15, priced at $534 found 4 days ago
United
Tue, Sep 30 - Sat, Oct 11
CPR
Casper
SDY
Sidney
$539 Roundtrip, found 4 days ago
$539
Roundtrip
found 4 days ago
Select United flight, departing Tue, Sep 30 from Casper to Sidney, returning Sat, Oct 11, priced at $539 found 4 days ago
United
Thu, Sep 25 - Sat, Oct 11
CPR
Casper
SDY
Sidney
$544 Roundtrip, found 4 days ago
$544
Roundtrip
found 4 days ago
Select United flight, departing Thu, Sep 25 from Casper to Sidney, returning Sat, Oct 11, priced at $544 found 4 days ago
United
Tue, Sep 23 - Sat, Oct 4
CPR
Casper
SDY
Sidney
$554 Roundtrip, found 4 days ago
$554
Roundtrip
found 4 days ago
Select United flight, departing Tue, Sep 23 from Casper to Sidney, returning Sat, Oct 4, priced at $554 found 4 days ago
United
Wed, Sep 17 - Sat, Oct 4
CPR
Casper
SDY
Sidney
$579 Roundtrip, found 4 days ago
$579
Roundtrip
found 4 days ago
Select United flight, departing Wed, Sep 17 from Casper to Sidney, returning Sat, Oct 4, priced at $579 found 4 days ago
United
Thu, Oct 30 - Sat, Nov 15
CPR
Casper
SDY
Sidney
$599 Roundtrip, found 4 days ago
$599
Roundtrip
found 4 days ago
Select United flight, departing Thu, Oct 30 from Casper to Sidney, returning Sat, Nov 15, priced at $599 found 4 days ago
United
Mon, Oct 27 - Sat, Nov 8
CPR
Casper
SDY
Sidney
$619 Roundtrip, found 4 days ago
$619
Roundtrip
found 4 days ago
Select United flight, departing Mon, Oct 27 from Casper to Sidney, returning Sat, Nov 8, priced at $619 found 4 days ago
United
Tue, Sep 16 - Wed, Oct 1
CPR
Casper
SDY
Sidney
$629 Roundtrip, found 4 days ago
$629
Roundtrip
found 4 days ago
Select United flight, departing Tue, Sep 16 from Casper to Sidney, returning Wed, Oct 1, priced at $629 found 4 days ago
United
Tue, Sep 16 - Mon, Sep 29
CPR
Casper
SDY
Sidney
$634 Roundtrip, found 4 days ago
$634
Roundtrip
found 4 days ago
Select United flight, departing Tue, Sep 16 from Casper to Sidney, returning Mon, Sep 29, priced at $634 found 4 days ago
United
Tue, Sep 16 - Sat, Sep 27
CPR
Casper
SDY
Sidney
$639 Roundtrip, found 4 days ago
$639
Roundtrip
found 4 days ago
Select United flight, departing Tue, Sep 16 from Casper to Sidney, returning Sat, Sep 27, priced at $639 found 4 days ago

Alternative airports near Sidney

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Sidney-Richland Municipal SDY. Cheapest and Closest option available. Average driving time to city center is 3 minutes. Flights from $544
SDY
Sidney-Richland Municipal
CheapestClosest
Average driving time to city center3 min
Flights from $544
Flights from Casper (CPR) to Sidney (SDY)
Origin airport
Natrona County Intl.
Destination airport
Sidney-Richland Municipal
Roundtrip price
$533
Distance
350 mi

Casper to Sidney Flights

The cheapest times to fly from Casper to Sidney

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Casper to Sidney are during the month of October. You can find some of the cheapest flights from Casper to Sidney with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Casper to Sidney

Sunday is one of the best days to book for cheap flights from Casper to Sidney: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Casper to Sidney

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Casper to Sidney in 2025. You can also book with separate airlines for your outbound and return journeys, from $273 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Casper to Sidney flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Casper to Sidney airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY) cost?
Secure a cheap one-way flight from $273 or cheap return flight from $534 from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY)?
October is the least expensive month to fly from CPR to SDY. Avoiding peak travel times is often the key to landing a great deal.
What is the cheapest airline that flies from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY)?
To find the cheapest airline that'll fly you from CPR to SDY, use Expedia's filter tool. Customize your search based on your travel style, such as preferred carriers and number of stops. You can then sort your results by "Price (lowest to highest)" to list the most affordable options first.
How many flights per day from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY)?
Nonstop flights from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY) aren't available daily, so you'll have to take a flight with a layover. Explore your options with Expedia's filters. Enter your travel details and click on either "1 Stop" or "2+ Stops."
What day of the week has the most flights from CPR to SDY?
Friday is generally the busiest day for flights, while Tuesday is often the quietest.* Just remember that flight schedules can change depending on various factors, including the carrier and season.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY)?
Select a flight from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY) that takes off before 3 PM to reduce the likelihood of delays and cancellations. Departures later than this have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY) last-minute?
Booking your flight from CPR to SDY just before your getaway is typically more expensive. However, if there's some wiggle room with your travel times and dates, you could snag a cheap last-minute fare.
Is it cheaper to book a CPR to SDY flight and hotel package?
Compared with arranging hotels and flights separately, booking a CPR to SDY flight and hotel package with Expedia could lead to significant savings. Better still, having everything in one place will take the hassle out of travel planning. Just pick your flights and choose from our extensive range of hotels, then tailor your trip with other add-ons like car rentals and activities.
Can I cancel or change the date of my flight from Natrona County Intl. Airport (CPR) to Sidney-Richland Municipal Airport (SDY)?
It's generally possible to reschedule or cancel your CPR to SDY flight. However, if the booking was made more than 24 hours ago, additional charges may apply. Refer to your airline's policies in your itinerary to see what changes are allowed and if any costs are involved. You'll also find further details on our Customer Service portal.

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*Available to One Key members.