$312 Cheap Flights from Sidney (SDY) to Denver (DEN)

View $312 flight on Wed, Jun 10, 2026Opens in a new window

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

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Cheap Flights from Sidney to Denver (SDY-DEN)

Prices were available within the past 7 days and start at $312 for one-way flights and $525 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Cape Air
Wed, Jun 10 - Mon, Jun 15
SDY
Sidney
DEN
Denver
$525 Roundtrip, found 1 day ago
$525
Roundtrip
found 1 day ago
Select Cape Air flight, departing Wed, Jun 10 from Sidney to Denver, returning Mon, Jun 15, priced at $525 found 1 day ago
Cape Air
Mon, Jun 15 - Tue, Jun 23
SDY
Sidney
DEN
Denver
$536 Roundtrip, found 5 days ago
$536
Roundtrip
found 5 days ago
Select Cape Air flight, departing Mon, Jun 15 from Sidney to Denver, returning Tue, Jun 23, priced at $536 found 5 days ago
Cape Air
Wed, Jun 10 - Mon, Jun 15
SDY
Sidney
DEN
Denver
$550 Roundtrip, found 1 day ago
$550
Roundtrip
found 1 day ago
Select Cape Air flight, departing Wed, Jun 10 from Sidney to Denver, returning Mon, Jun 15, priced at $550 found 1 day ago
Cape Air
Wed, May 27 - Mon, Jun 1
SDY
Sidney
DEN
Denver
$560 Roundtrip, found 4 days ago
$560
Roundtrip
found 4 days ago
Select Cape Air flight, departing Wed, May 27 from Sidney to Denver, returning Mon, Jun 1, priced at $560 found 4 days ago
Cape Air
Thu, Apr 9 - Tue, Apr 14
SDY
Sidney
DEN
Denver
$586 Roundtrip, found 5 days ago
$586
Roundtrip
found 5 days ago
Select Cape Air flight, departing Thu, Apr 9 from Sidney to Denver, returning Tue, Apr 14, priced at $586 found 5 days ago
Cape Air
Wed, Apr 8 - Mon, Apr 20
SDY
Sidney
DEN
Denver
$599 Roundtrip, found 4 days ago
$599
Roundtrip
found 4 days ago
Select Cape Air flight, departing Wed, Apr 8 from Sidney to Denver, returning Mon, Apr 20, priced at $599 found 4 days ago
Cape Air
Wed, Apr 8 - Mon, Apr 20
SDY
Sidney
DEN
Denver
$609 Roundtrip, found 4 days ago
$609
Roundtrip
found 4 days ago
Select Cape Air flight, departing Wed, Apr 8 from Sidney to Denver, returning Mon, Apr 20, priced at $609 found 4 days ago
Cape Air
Wed, Jun 10 - Mon, Jun 15
SDY
Sidney
DEN
Denver
$621 Roundtrip, found 4 days ago
$621
Roundtrip
found 4 days ago
Select Cape Air flight, departing Wed, Jun 10 from Sidney to Denver, returning Mon, Jun 15, priced at $621 found 4 days ago
Cape Air
Thu, Apr 9 - Sun, Apr 12
SDY
Sidney
DEN
Denver
$626 Roundtrip, found 4 days ago
$626
Roundtrip
found 4 days ago
Select Cape Air flight, departing Thu, Apr 9 from Sidney to Denver, returning Sun, Apr 12, priced at $626 found 4 days ago
Cape Air
Mon, Jun 15 - Tue, Jun 23
SDY
Sidney
DEN
Denver
$634 Roundtrip, found 4 days ago
$634
Roundtrip
found 4 days ago
Select Cape Air flight, departing Mon, Jun 15 from Sidney to Denver, returning Tue, Jun 23, priced at $634 found 4 days ago

Frequently asked questions

How much does a flight from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) cost?
You can find cheap one-way flights from $312 and cheap return flights from $525 SDY to DEN with Expedia. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see our cheapest fares first, and use the Price Tracking tool to receive alerts when SDY to DEN ticket fares go up or down.
What is the cheapest month to fly from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
The cheapest month to fly from SDY to DEN is June when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you're able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
Enter SDY to DEN and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
How do I find cheap flights from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
To find a cheap flight from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
What is the earliest flight from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
The earliest flight from Sidney, MT (SDY) to Denver, CO (DEN) usually leaves at around 7:35 AM, operated by 9K and American Airlines. This seasonal service is available in June, and an early departure can help you maximize your time in Denver. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What day of the week has the most flights from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
You'll usually find the most flights from Sidney-Richland Municipal (SDY) to Denver Intl. (DEN) on a Monday, with around 3 flights available. This gives you plenty of options for your travel plans.
What are the most popular departure times for flights from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
The most popular departure times for flights from Sidney, MT (SDY) to Denver, CO (DEN) are in the early afternoon, from 12pm to 3pm. This accounts for about 89% of total traffic. The only major carrier offering flights during this window is United Airlines. This timing is favored because it allows for a convenient travel schedule for those heading to Denver.
How long does it take to fly from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
Flying from SDY to DEN with a connection usually takes about 6 hours 50 minutes, traveling roughly 544 miles. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
Select the "Business class" and "First class" filters when looking for SDY to DEN flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
How do I earn miles on a Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) flight with Expedia?
It's easy to earn miles on a Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Denver from Sidney-Richland Municipal (SDY)?
From Sidney-Richland Municipal (SDY), you can fly into Denver Intl. (DEN) to reach Denver. Some flights may connect through major hubs like Logan Intl. (BIL) before reaching Denver. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) at the last minute?
Typically, booking a last minute flight from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) flight and hotel package?
Securing a Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) Denver Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.)?
If you booked your Sidney, MT (SDY-Sidney-Richland Municipal) to Denver, CO (DEN-Denver Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Sidney-Richland Municipal
Destination airport
Denver Intl.
Roundtrip price
$525
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 June. 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 2026. You can also book with separate airlines for your outbound and return journeys, from $312 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

*Flight schedules are subject to change.

*Available to One Key members.

 

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