United Flight 1866 Deals & Information (2026/2027)

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United Flight 1866 Route Deals From $140

The cheapest prices found with in the last 7 days for return flights were $319 and $140 for one-way flights to Denver Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Thu, Oct 15 - Sun, Oct 25
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$319 Roundtrip, found 17 hours ago
$319
Roundtrip
found 17 hours ago
Select United flight, departing Thu, Oct 15 from Greenville-Spartanburg Intl. to Denver Intl., returning Sun, Oct 25, priced at $319 found 17 hours ago
Tue, Sep 29 - Tue, Oct 6
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$324 Roundtrip, found 1 day ago
$324
Roundtrip
found 1 day ago
Select United flight, departing Tue, Sep 29 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Oct 6, priced at $324 found 1 day ago
Sat, Oct 24 - Sat, Oct 31
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$324 Roundtrip, found 4 days ago
$324
Roundtrip
found 4 days ago
Select United flight, departing Sat, Oct 24 from Greenville-Spartanburg Intl. to Denver Intl., returning Sat, Oct 31, priced at $324 found 4 days ago
Thu, Oct 15 - Sun, Oct 25
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$329 Roundtrip, found 17 hours ago
$329
Roundtrip
found 17 hours ago
Select United flight, departing Thu, Oct 15 from Greenville-Spartanburg Intl. to Denver Intl., returning Sun, Oct 25, priced at $329 found 17 hours ago
Wed, Aug 26 - Wed, Sep 2
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$334 Roundtrip, found 11 hours ago
$334
Roundtrip
found 11 hours ago
Select United flight, departing Wed, Aug 26 from Greenville-Spartanburg Intl. to Denver Intl., returning Wed, Sep 2, priced at $334 found 11 hours ago
Tue, Oct 27 - Sat, Oct 31
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$334 Roundtrip, found 5 days ago
$334
Roundtrip
found 5 days ago
Select United flight, departing Tue, Oct 27 from Greenville-Spartanburg Intl. to Denver Intl., returning Sat, Oct 31, priced at $334 found 5 days ago
Thu, Oct 15 - Sun, Oct 25
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$346 Roundtrip, found 17 hours ago
$346
Roundtrip
found 17 hours ago
Select United flight, departing Thu, Oct 15 from Greenville-Spartanburg Intl. to Denver Intl., returning Sun, Oct 25, priced at $346 found 17 hours ago
Wed, Aug 26 - Wed, Sep 2
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$351 Roundtrip, found 11 hours ago
$351
Roundtrip
found 11 hours ago
Select United flight, departing Wed, Aug 26 from Greenville-Spartanburg Intl. to Denver Intl., returning Wed, Sep 2, priced at $351 found 11 hours ago
Wed, Sep 9 - Tue, Sep 15
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$353 Roundtrip, found 3 days ago
$353
Roundtrip
found 3 days ago
Select United flight, departing Wed, Sep 9 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Sep 15, priced at $353 found 3 days ago
Wed, Aug 26 - Wed, Sep 2
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$354 Roundtrip, found 11 hours ago
$354
Roundtrip
found 11 hours ago
Select United flight, departing Wed, Aug 26 from Greenville-Spartanburg Intl. to Denver Intl., returning Wed, Sep 2, priced at $354 found 11 hours ago
Wed, Sep 9 - Tue, Sep 15
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$355 Roundtrip, found 3 days ago
$355
Roundtrip
found 3 days ago
Select United flight, departing Wed, Sep 9 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Sep 15, priced at $355 found 3 days ago
Thu, Oct 15 - Sun, Oct 25
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$356 Roundtrip, found 17 hours ago
$356
Roundtrip
found 17 hours ago
Select United flight, departing Thu, Oct 15 from Greenville-Spartanburg Intl. to Denver Intl., returning Sun, Oct 25, priced at $356 found 17 hours ago
Wed, Sep 9 - Tue, Sep 15
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$358 Roundtrip, found 3 days ago
$358
Roundtrip
found 3 days ago
Select United flight, departing Wed, Sep 9 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Sep 15, priced at $358 found 3 days ago
Wed, Aug 26 - Wed, Sep 2
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$361 Roundtrip, found 11 hours ago
$361
Roundtrip
found 11 hours ago
Select United flight, departing Wed, Aug 26 from Greenville-Spartanburg Intl. to Denver Intl., returning Wed, Sep 2, priced at $361 found 11 hours ago
Tue, Sep 29 - Tue, Oct 6
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$362 Roundtrip, found 1 day ago
$362
Roundtrip
found 1 day ago
Select United flight, departing Tue, Sep 29 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Oct 6, priced at $362 found 1 day ago
Wed, Sep 9 - Tue, Sep 15
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$363 Roundtrip, found 3 days ago
$363
Roundtrip
found 3 days ago
Select United flight, departing Wed, Sep 9 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Sep 15, priced at $363 found 3 days ago
Thu, Sep 17 - Tue, Sep 22
GSP
Greenville-Spartanburg Intl.
DEN
Denver Intl.
$364 Roundtrip, found 3 days ago
$364
Roundtrip
found 3 days ago
Select United flight, departing Thu, Sep 17 from Greenville-Spartanburg Intl. to Denver Intl., returning Tue, Sep 22, priced at $364 found 3 days ago

Frequently asked questions

What route does flight number UA1866 take?
Flight number UA1866 flies straight from Denver, CO Airport (DEN-Denver Intl.) to PHX. During this trip, you'll be in the air for 1 hour and 54 minutes. Book ahead to lock in your favorite seat.
How often is UA1866 on time?
About 81% of UA1866 flights head off on time — so if you're traveling between Denver, CO Airport (DEN-Denver Intl.) and Sky Harbor Intl. Airport (PHX), you can breathe easy knowing that you'll reach your destination as quickly as possible. If this United Airlines flight runs behind time, the average wait is approximately 19 minutes. Thanks to the carrier's first-rate service, this route has a star rating of 2.75.
What kind of plane is on flight number UA1866?
Expect to hop on board a Boeing 737 MAX 9 if you're traveling on flight UA1866. Nearly all services from DIA airport to Phoenix Sky Harbor Intl. Airport are operated using this aircraft type.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA1866 flight with Travelocity, please visit our Customer Service Portal.