Flights Ontario → Denver
As of October 2026, economy flights from Ontario to Denver have a typical range USD 379–832, median USD 566. Full range across all 241 offers: USD 213–2379. We analyzed 241 offers from 7 airlines in a single price check.
Preview snapshot — prices change. Search for live results.
Data collected by LetsFG's multi-source price checks — every airline and the major booking sites checked for this route. How we collect data →
Best offers by airline: Ontario → Denver
Based on 241 offers · October 2026. Prices and availability change — run a live search to confirm.
Bag & seat fees: Ontario → Denver
Add-on pricing from the cheapest available offer per airline · October 2026 · USD
| Airline | Carry-on | Checked bag | Seat selection |
|---|---|---|---|
| Frontier Airlines | — | — | — |
| United | Included | USD 35 | — |
| Southwest Airlines | Included | Included | — |
| Delta | Included | USD 35 | — |
| American Airlines | Included | USD 35 | — |
| Alaska Airlines | Included | USD 35 | — |
Fees are estimates from the prices we checked and may not reflect your specific itinerary, booking class, or payment method. Run a live search for exact pricing.
How much do flights from Ontario to Denver cost?
Based on 241 offers · October 2026
Ontario to Denver flights ranged from USD 213 to USD 2379 across 241 offers analyzed in October 2026. The chart below shows how prices distributed across all 241 offers.
These 241 offers (October 2026) span multiple departure dates and booking windows — your travel dates may fall anywhere in this distribution. Only a live search shows where your specific trip lands.
50% of offers priced between USD 504 and USD 643
What hidden fees do Ontario to Denver flights charge?
Ancillary fees — bags, seat selection, and payment surcharges — can add 10–25% to the base fare on Ontario to Denver routes. The breakdown below is based on 241 offers analyzed in October 2026.
| Carrier | Avg fee (USD) | % of base fare |
|---|---|---|
| F9 | 10 | 2% |
| UA | 45 | 5% |
| WN | 0 | 0% |
| DL | 45 | 3% |
| AA | 45 | 6% |
| AS | 45 | 4% |
American Airlines: base ~USD 588 + fees USD 45 = ~USD 633 total. Delta Air Lines: base ~USD 841 + fees USD 45 = ~USD 886 total.
Total costs diverge further when fees are added on this route. Always compare total cost, not just the advertised base fare.
Estimates based on median total minus average ancillary fee. Actual base fares vary by itinerary.Fee levels vary significantly across carriers on this route — some carriers charge 50%+ above the base fare in ancillary fees.
Run your search to see itemized fees for your itineraryWhich airline is cheapest from Ontario to Denver?
7 airlines flew Ontario to Denver in this dataset. Knowing the airline isn't enough — the typical fare range below shows how far prices swing on each one. Median and range include all fees we recorded.
Even on the cheapest airline (Frontier), fares ranged USD 214–218 in this snapshot. Your exact price depends on your dates and how far ahead you book — run a live search to see your number →
| Airline | Offers | Typical range (USD) | Median (USD) | Fees (USD) |
|---|---|---|---|---|
 Frontier | 8 | 214–218 | 214 | n/a |
 Frontier Airlines | 26 | 218–559 | 374 | 10 (3%) |
 Southwest Airlines | 162 | 441–649 | 566 | 0 (0%) |
 American Airlines | 25 | 509–926 | 633 | 45 (7%) |
 Delta Air Lines | 5 | 478–2379 | 886 | 45 (5%) |
 United Airlines | 9 | 454–1131 | 1000 | 45 (5%) |
 Alaska Airlines | 6 | 963–1567 | 1233 | 45 (4%) |
Where do the best Ontario → Denver prices come from?
We checked direct airlines, travel agencies, and meta-search for this route. On this route the lowest median came from travel agency sources, but the cheapest channel shifts by route and date — which is exactly why a live search across all of them wins.
We compare every airline and the major booking sites but never disclose which — that's our edge. Prices are the ones we observed and aren't official data from any platform. Run a live search and we bring you the cheapest, wherever it is.
Key facts: Ontario to Denver flights
- Full-service carriers on Ontario–Denver cost 2.4x more than budget airlines (USD 938 vs USD 385 median; overall median USD 566).
- UA charges 4.5x more in ancillary fees than F9 — USD 45 vs USD 10 avg per booking.
- The same route priced USD 355 apart depending on where it was booked — the lowest median was USD 214. We search every airline and the major booking sites at once so you always see that lowest price.
Frequently asked questions
- How much does a flight from Ontario to Denver cost?
- Based on 241 offers analyzed, Ontario to Denver flights range from USD 213 to USD 2379, with a median price of USD 566. Search for your specific dates →
- What hidden fees should I expect on Ontario to Denver flights?
- On average, ancillary fees (bags, seat selection) add USD 10 to the base fare on Ontario to Denver flights. See itemized fees for your itinerary →
- Which airline is cheapest on Ontario to Denver including all fees?
- Frontier has the lowest median fare on Ontario to Denver at USD 214 (median across 8 offers in our snapshot). Check which airline wins on your dates →
- Which booking site has the cheapest Ontario–Denver flights?
- It depends on your dates — no single site is always cheapest. We search every airline and the major booking sites at once (travel agencies and meta-search included) and surface whichever is lowest; the best median in this snapshot was USD 214. Run a live search and we'll find the cheapest for you →
- Why do prices vary so much on Ontario to Denver routes?
- Ontario to Denver has 7 airlines competing, creating a price range from USD 213 to USD 2379 across 241 offers. Prices on this route change with booking timing, advance purchase, and ancillary add-ons. Find where your trip lands in the distribution →
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