$290 Cheap Flights from Sidney (SDY) to Denver (DEN)

View $290 flight on Mon, Jan 19, 2026Opens in a new window

Popular airlines from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver Intl. Airport (DEN)

Cheap Flights from Sidney to Denver (SDY-DEN)

Prices were available within the past 7 days and start at $290 for one-way flights and $316 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Cape Air
Wed, Jan 14 - Wed, Jan 21
SDY
Sidney
DEN
Denver
$316 Roundtrip, found 1 day ago
$316
Roundtrip
found 1 day ago
Select Cape Air flight, departing Wed, Jan 14 from Sidney to Denver, returning Wed, Jan 21, priced at $316 found 1 day ago
Cape Air
Sun, Nov 9 - Sun, Nov 16
SDY
Sidney
DEN
Denver
$321 Roundtrip, found 5 days ago
$321
Roundtrip
found 5 days ago
Select Cape Air flight, departing Sun, Nov 9 from Sidney to Denver, returning Sun, Nov 16, priced at $321 found 5 days ago
Cape Air
Mon, Nov 10 - Sat, Nov 15
SDY
Sidney
DEN
Denver
$326 Roundtrip, found 5 days ago
$326
Roundtrip
found 5 days ago
Select Cape Air flight, departing Mon, Nov 10 from Sidney to Denver, returning Sat, Nov 15, priced at $326 found 5 days ago
Cape Air
Thu, Nov 6 - Fri, Nov 14
SDY
Sidney
DEN
Denver
$356 Roundtrip, found 5 days ago
$356
Roundtrip
found 5 days ago
Select Cape Air flight, departing Thu, Nov 6 from Sidney to Denver, returning Fri, Nov 14, priced at $356 found 5 days ago
Cape Air
Wed, Jan 14 - Wed, Jan 21
SDY
Sidney
DEN
Denver
$386 Roundtrip, found 1 day ago
$386
Roundtrip
found 1 day ago
Select Cape Air flight, departing Wed, Jan 14 from Sidney to Denver, returning Wed, Jan 21, priced at $386 found 1 day ago
Cape Air
Wed, Jan 14 - Wed, Jan 21
SDY
Sidney
DEN
Denver
$405 Roundtrip, found 3 days ago
$405
Roundtrip
found 3 days ago
Select Cape Air flight, departing Wed, Jan 14 from Sidney to Denver, returning Wed, Jan 21, priced at $405 found 3 days ago
Cape Air
Wed, Jan 14 - Wed, Jan 21
SDY
Sidney
DEN
Denver
$442 Roundtrip, found 3 days ago
$442
Roundtrip
found 3 days ago
Select Cape Air flight, departing Wed, Jan 14 from Sidney to Denver, returning Wed, Jan 21, priced at $442 found 3 days ago
Cape Air
Sun, Nov 9 - Sun, Nov 16
SDY
Sidney
DEN
Denver
$447 Roundtrip, found 5 days ago
$447
Roundtrip
found 5 days ago
Select Cape Air flight, departing Sun, Nov 9 from Sidney to Denver, returning Sun, Nov 16, priced at $447 found 5 days ago
Cape Air
Sun, Nov 9 - Sun, Nov 16
SDY
Sidney
DEN
Denver
$451 Roundtrip, found 5 days ago
$451
Roundtrip
found 5 days ago
Select Cape Air flight, departing Sun, Nov 9 from Sidney to Denver, returning Sun, Nov 16, priced at $451 found 5 days ago
Cape Air
Wed, Jan 14 - Wed, Jan 21
SDY
Sidney
DEN
Denver
$464 Roundtrip, found 1 day ago
$464
Roundtrip
found 1 day ago
Select Cape Air flight, departing Wed, Jan 14 from Sidney to Denver, returning Wed, Jan 21, priced at $464 found 1 day ago

Frequently asked questions

How much does a flight from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN) cost?
Get a cheap one-way flight from $290 or cheap return flight from $316 from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight deals on this route.
What is the cheapest month to fly from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN)?
Flying in January can help you save, as it's the cheapest month for flights between SDY and DEN. You'll usually find the lowest prices during off-peak months.
Which airlines fly direct from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN)?
You can't fly nonstop from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver Intl. Airport (DEN). However, you can easily journey to Denver without any layovers by leaving from Basin Intl. Airport (XWA).
What is the cheapest airline that flies from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN)?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from SDY to DEN. Then, sort your results by "Price (lowest to highest)" to score a good deal.
How many flights per day from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN)?
There aren't any daily nonstop flights available from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN). But you can opt for flights with layovers. Filter your search on Expedia to include one or more stops, and you'll be soaring above the clouds in no time.
What day of the week has the most flights from SDY to DEN?
Friday is typically the busiest day for flights, while Tuesday is often the quietest.* Keep in mind that flight schedules can vary based on a range of factors, including the season and airline.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN)?
Select a flight from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN) that leaves before 3 PM to reduce the risk of delays and cancellations. Departures after this time 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 Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN) last-minute?
Booking your plane ticket from SDY to DEN shortly before your trip is generally more expensive. However, if you're flexible with your departure times and dates, you could score a cheap last-minute fare.
Is it cheaper to book a SDY to DEN flight and hotel package?
You'll typically save money by securing a SDY to DEN flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's simple to manage it all in one convenient place. Once you've chosen your ideal flights and accommodations, you can add extras such as tours, car rentals and activities.
Can I cancel or change the date of my flight from Sidney-Richland Municipal Airport (SDY) to Denver Intl. Airport (DEN)?
If you booked your SDY to DEN flight within the last 24 hours, you may be able to modify or cancel it at no cost. Depending on the airline and the type of fare you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, visit our Customer Service portal for more details.

Travel information

Origin airport
Sidney-Richland Municipal
Destination airport
Denver Intl.
Roundtrip price
$316
Distance
543 mi

Book with confidence

Sidney to Denver Flights

The cheapest times to fly from Sidney to Denver

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 Sidney to Denver are during the month of January. You can find some of the cheapest flights from Sidney to Denver with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Sidney to Denver

Sunday is one of the best days to book for cheap flights from Sidney to Denver: 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 Sidney to Denver

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 Sidney to Denver in 2025. You can also book with separate airlines for your outbound and return journeys, from $290 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 Sidney to Denver 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 Sidney to Denver 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.

 

Sidney to Denver Flights

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*Available to One Key members.