Ontario to Sydney ONT → SYD
Ontario International Airport (ONT) → Sydney (Kingsford Smith) Airport (SYD)
The cheapest return found recently is $3,328 with United Airlines, 19 Dec – 5 Jan 2027, found today.
Return
The cheapest return fare on each of 3 departure dates is usually $1,198 to $2,265.
Cheapest return found recently
$3,328
19 Dec – 5 Jan 2027 · United Airlines
Ontario International Airport (ONT) → Sydney (Kingsford Smith) Airport (SYD)
Leaves 6:27 p.m. · Return leaves 11:20 a.m. · 54 h 38 min of travel, both ways together
out 1 stop, back nonstop
found today
Cheapest nonstop return
None seen yet.
Found recently, and the cheapest we hold
$3,328 19 Dec – 5 Jan 2027found todaySee prices for these dates
$1,194 9 Nov – 22 Novfound 4 days agoSee prices for these dates
What have prices looked like?
Over 25 days, 24 Sept to 18 Oct, the cheapest return we saw each day was $987 to $1,540.
At $3,328, the cheapest return found recently is above that range.
25 days is a short history, so treat this range as an early guide.
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 3 departure dates from 22 Oct to 19 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 17-night return fares leaving within 3 days of 19 Dec to compare.
Every date we hold
3 fares on 3 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 22 Oct – 29 Oct | $1,201 | Alaska Airlines | Ontario International Airport (ONT) → Sydney (Kingsford Smith) Airport (SYD) | out 1 stop, back nonstop | found 5 days ago | See prices for these dates |
| 9 Nov – 22 Nov | $1,194 | United Airlines | Ontario International Airport (ONT) → Sydney (Kingsford Smith) Airport (SYD) | out 1 stop, back 1 stop | found 4 days ago | See prices for these dates |
| 19 Dec – 5 Jan 2027 | $3,328 | United Airlines | Ontario International Airport (ONT) → Sydney (Kingsford Smith) Airport (SYD) | out 1 stop, back nonstop | found today | See prices for these dates |
Which month looks cheapest?
November 2026 is the cheapest month — from $1,194.
Airlines on the cheapest dates: United Airlines, Alaska Airlines.
Premium cabin fares from Ontario to Sydney
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 19 Dec – 5 Jan 2027 in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for Ontario to Sydney?
Return
Fares 90 to 179 days before departure were typically 16% lower than 7 to 13 days before departure.
From the cheapest return each day between 24 Sept and 18 Oct (25 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 |
|---|---|---|---|---|
| 7–13 days | $1,241 | $1,110 | +19% | 11 |
| 14–29 days | $1,194 | $1,073 | +14% | 11 |
| 30–59 days | $1,130 | $999 | +8% | 21 |
| 60–89 days | $1,511 | $1,145 | +45% | 21 |
| 90–179 days | $1,044 | $987 | Cheapest seen | 25 |
| 180+ days | $1,303 | $1,167 | +25% | 21 |
Could a nearby airport be cheaper?
A different airport at either end can change the fare — sometimes a lot.
Return
Los Angeles → Sydney
56 km from Ontario
$2,178
$1,150 less than flying from Ontario
19 Dec – 5 Jan 2027 · LAX → SYD · out 1 stop, back 1 stop
found today
Long Beach → Sydney
60 km from Ontario
$3,002
$326 less than flying from Ontario
19 Dec – 5 Jan 2027 · LGB → SYD · out 2 stops, back 1 stop
found today
Cheapest recent price on each route — round trip, per traveler in Economy. Distances are in a straight line.
Live price for these dates
The cheapest return found recently is for 19 Dec – 5 Jan 2027. A live search on this page shows what those dates cost now, for one adult in economy.
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