United Flight UA1840 Deals & Information (2025/2026)

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United Flight 1840 Route Deals From $39

The cheapest prices found with in the last 7 days for return flights were $79 and $39 for one-way flights to San Francisco Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Fri, Oct 24 - Mon, Oct 27
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$79 Roundtrip, found 1 hour ago
$79
Roundtrip
found 1 hour ago
Select United flight, departing Fri, Oct 24 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Oct 27, priced at $79 found 1 hour ago
Fri, Dec 5 - Sun, Dec 7
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$97 Roundtrip, just found
$97
Roundtrip
just found
Select United flight, departing Fri, Dec 5 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Sun, Dec 7, priced at $97 just found
Fri, Oct 31 - Mon, Nov 3
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$98 Roundtrip, found 7 hours ago
$98
Roundtrip
found 7 hours ago
Select United flight, departing Fri, Oct 31 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Nov 3, priced at $98 found 7 hours ago
Fri, Oct 31 - Mon, Nov 3
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$100 Roundtrip, found 7 hours ago
$100
Roundtrip
found 7 hours ago
Select United flight, departing Fri, Oct 31 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Nov 3, priced at $100 found 7 hours ago
Fri, Oct 24 - Mon, Oct 27
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$104 Roundtrip, found 1 hour ago
$104
Roundtrip
found 1 hour ago
Select United flight, departing Fri, Oct 24 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Oct 27, priced at $104 found 1 hour ago
Fri, Oct 24 - Mon, Oct 27
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$110 Roundtrip, found 1 hour ago
$110
Roundtrip
found 1 hour ago
Select United flight, departing Fri, Oct 24 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Oct 27, priced at $110 found 1 hour ago
Mon, Oct 27 - Mon, Nov 3
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$119 Roundtrip, found 1 day ago
$119
Roundtrip
found 1 day ago
Select United flight, departing Mon, Oct 27 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Nov 3, priced at $119 found 1 day ago
Fri, Oct 31 - Mon, Nov 3
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$129 Roundtrip, found 7 hours ago
$129
Roundtrip
found 7 hours ago
Select United flight, departing Fri, Oct 31 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Mon, Nov 3, priced at $129 found 7 hours ago
Sun, Nov 2 - Tue, Nov 4
ONT
Los Angeles - Ontario Intl.
SFO
San Francisco Intl.
$131 Roundtrip, found 1 hour ago
$131
Roundtrip
found 1 hour ago
Select United flight, departing Sun, Nov 2 from Los Angeles - Ontario Intl. to San Francisco Intl., returning Tue, Nov 4, priced at $131 found 1 hour ago