Cheap flights from Washington to Ontario from $103 DCA, IAD → ONT
Ronald Reagan National Airport (DCA), Washington Dulles International Airport (IAD) → Ontario International Airport (ONT)
The cheapest return found recently is $331 with Frontier Airlines, 10 Dec – 18 Dec, found 2 days ago. The cheapest one-way found recently is $103 with Frontier Airlines, 7 Feb 2027, found 4 days ago.
- Cheapest one-way found recently
- $103, found 4 days ago
- Cheapest return found recently
- $331, 10 Dec to 18 Dec
- Usual return price
- $402 to $497
- Cheapest month to fly
- December 2026, return fares from $323 found in the last 7 days
Return
The cheapest return fare on each of 6 departure dates is usually $402 to $497.
Cheapest return found recently
$331
10 Dec – 18 Dec · Frontier Airlines
Washington Dulles International Airport (IAD) → Ontario International Airport (ONT)
Leaves 8:55 p.m. · Return leaves 12:59 a.m. · 25 h 3 min of travel, both ways together
out 1 stop, back 1 stop
found 2 days ago
Cheapest nonstop return
None seen yet.
Found recently, and the cheapest we hold
$331 10 Dec – 18 Decfound 2 days agoSee prices for these dates
$323 10 Dec – 20 Decfound 4 days agoSee prices for these dates
What have prices looked like?
Over 46 days, 24 Sept to 11 Nov, the cheapest return we saw each day was $190 to $491.
Those were the prices on those days, not today's.
Is this a good return price?
Compared with the cheapest return fare on each of 6 departure dates from 16 Nov to 28 Dec, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
We hold no other 8-night return fares leaving within 3 days of 10 Dec to compare.
Every date we hold
64 fares on 6 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 16 Nov – 23 Nov | $506 | Frontier Airlines | Ronald Reagan National Airport (DCA) → Ontario International Airport (ONT) | out 1 stop, back 1 stop | found 4 days ago | See prices for these dates |
| 17 Nov – 30 Nov | $470 | Frontier Airlines | Ronald Reagan National Airport (DCA) → Ontario International Airport (ONT) | out 1 stop, back 1 stop | found 4 days ago | See prices for these dates |
| 30 Nov – 2 Dec | $395 | Frontier Airlines | Washington Dulles International Airport (IAD) → Ontario International Airport (ONT) | out 2 stops, back 1 stop | found 4 days ago | See prices for these dates |
| 10 Dec – 20 Dec | $323 | Frontier Airlines | Ronald Reagan National Airport (DCA) → Ontario International Airport (ONT) | out 1 stop, back 1 stop | found 4 days ago | See prices for these dates |
| 24 Dec – 30 Dec | $422 | Frontier Airlines | Washington Dulles International Airport (IAD) → Ontario International Airport (ONT) | out 1 stop, back 1 stop | found 5 days ago | See prices for these dates |
| 28 Dec – 2 Jan 2027 | $612 | Frontier Airlines | Washington Dulles International Airport (IAD) → Ontario International Airport (ONT) | out 1 stop, back 1 stop | found 6 days ago | See prices for these dates |
Which month looks cheapest?
December 2026 is the cheapest month — from $323.
Airlines on the cheapest dates: Frontier Airlines.
One-way
Not enough comparable prices yet for a usual one-way price.
Cheapest one-way found recently
$103
7 Feb 2027 · Frontier Airlines
Ronald Reagan National Airport (DCA) → Ontario International Airport (ONT)
Leaves 6:00 p.m. · 9 h 5 min trip
stops unknown
found 4 days ago
Cheapest nonstop one-way
None seen yet.
Found recently, and the cheapest we hold
$103 7 Feb 2027found 4 days agoOpen this trip
It is also the cheapest one-way we hold, of any age.
What have prices looked like?
Over 34 days, 1 Oct to 9 Nov, the cheapest one-way we saw each day was $86 to $294.
Those were the prices on those days, not today's.
Is this a good one-way price?
Not enough comparable prices yet: we hold one-way fares on 1 departure date and need at least 3 to say what is usual.
Could nearby dates be cheaper?
We hold no other one-way fares leaving within 3 days of 7 Feb 2027 to compare.
Every date we hold
1 fares on 1 departure dates
See every date as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 7 Feb 2027 | $103 | Frontier Airlines | Ronald Reagan National Airport (DCA) → Ontario International Airport (ONT) | stops unknown | found 4 days ago | Open this trip |
Airlines on the cheapest dates: Frontier Airlines.
Premium cabin fares from Washington to Ontario
We hold no premium economy, business or first-class fares for this route: we collect them for the busiest routes, and this one is not among them yet.
Today's prices for 10 Dec – 18 Dec in another cabin: Premium economy · Business · First
Today's prices for 7 Feb 2027 in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for Washington to Ontario?
Return
Fares 14 to 29 days before departure were typically 28% lower than 0 to 6 days before departure.
From the cheapest return each day between 24 Sept and 11 Nov (46 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 0–6 days | $337 | $334 | +39% | 18 |
| 7–13 days | $394 | $190 | +62% | 14 |
| 14–29 days | $243 | $222 | Cheapest seen | 20 |
| 30–59 days | $422 | $247 | +74% | 23 |
| 60–89 days | $309 | $290 | +27% | 19 |
One-way
Fares 30 to 59 days before departure were typically 16% lower than 14 to 29 days before departure.
From the cheapest one-way each day between 1 Oct and 9 Nov (34 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 14–29 days | $123 | $86 | +19% | 16 |
| 30–59 days | $103 | $86 | Cheapest seen | 17 |
| 60–89 days | $266 | $133 | +158% | 12 |
| 90–179 days | $183 | $103 | +77% | 10 |
Could a nearby airport be cheaper?
A different airport at either end can change the fare — sometimes a lot.
Return
Washington → Los Angeles
56 km from Ontario
$295
$36 less than flying to Ontario
10 Jan 2027 – 14 Jan 2027 · IAD → LAX · out 3 stops, back 1 stop
found 2 days ago
Baltimore → Ontario
57 km from Washington
$435
$104 more than flying from Washington
18 Nov – 30 Nov · BWI → ONT · out 1 stop, back 1 stop
found 4 days ago
Cheapest recent price on each route — round trip, per traveler in Economy. Distances are in a straight line.
One-way
Washington → Los Angeles
56 km from Ontario
$161
$58 more than flying to Ontario
18 Nov · DCA → LAX · stops unknown
found 2 days ago
Lancaster → Ontario
142 km from Washington
$476
$373 more than flying from Washington
17 Nov · LNS → ONT · 2 stops
found 6 days ago
Cheapest recent price on each route — one way, per traveler in Economy. Distances are in a straight line.
Live price for these dates
The cheapest return found recently is for 10 Dec – 18 Dec. A live search on this page shows what those dates cost now, for one adult in economy.
Questions about this trip
How much is a return flight from Washington to Ontario?
The cheapest return found recently is $331 with Frontier Airlines, 10 Dec to 18 Dec, found 2 days ago. The cheapest return we hold, of any age, is $323 with Frontier Airlines, 10 Dec to 20 Dec, found 4 days ago. The cheapest return fare on each of 6 departure dates is usually $402 to $497.
How much is a one-way flight from Washington to Ontario?
The cheapest one-way found recently is $103 with Frontier Airlines, 7 Feb 2027, found 4 days ago.
What is the cheapest month to fly from Washington to Ontario?
December 2026 is the cheapest month for a return, from $323, 10 Dec to 20 Dec, found 4 days ago.
How far ahead should I book a flight from Washington to Ontario?
In 46 days of prices between 24 Sept and 11 Nov, return fares 14 to 29 days before departure were typically 28% lower than 0 to 6 days before departure. In 34 days of prices between 1 Oct and 9 Nov, one-way fares 30 to 59 days before departure were typically 16% lower than 14 to 29 days before departure.
Which airlines have the cheapest flights from Washington to Ontario?
Between 16 Nov and 28 Dec, Frontier Airlines has the cheapest return on all 6 departure dates we hold.
Prices are what travelers' searches on Aviasales found in the last 7 days, in US dollars: the price the seller showed on Aviasales; bags may cost extra. Fares change, so check today's price before you book. How our prices work