United Flight 1521 Deals & Information (2026/2027)

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United Flight 1521 Route Deals From $284

The cheapest prices found with in the last 7 days for return flights were $297 and $284 for one-way flights to Denver Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, Aug 18 - Sun, Aug 23
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$297 Roundtrip, found 1 day ago
$297
Roundtrip
found 1 day ago
Select United flight, departing Tue, Aug 18 from James M. Cox Dayton Intl. to Denver Intl., returning Sun, Aug 23, priced at $297 found 1 day ago
Thu, Jul 9 - Sun, Jul 19
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$307 Roundtrip, found 23 hours ago
$307
Roundtrip
found 23 hours ago
Select United flight, departing Thu, Jul 9 from James M. Cox Dayton Intl. to Denver Intl., returning Sun, Jul 19, priced at $307 found 23 hours ago
Thu, May 7 - Tue, May 12
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$309 Roundtrip, found 18 hours ago
$309
Roundtrip
found 18 hours ago
Select United flight, departing Thu, May 7 from James M. Cox Dayton Intl. to Denver Intl., returning Tue, May 12, priced at $309 found 18 hours ago
Wed, Sep 9 - Mon, Sep 14
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$316 Roundtrip, found 6 days ago
$316
Roundtrip
found 6 days ago
Select United flight, departing Wed, Sep 9 from James M. Cox Dayton Intl. to Denver Intl., returning Mon, Sep 14, priced at $316 found 6 days ago
Thu, May 7 - Tue, May 12
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$319 Roundtrip, found 18 hours ago
$319
Roundtrip
found 18 hours ago
Select United flight, departing Thu, May 7 from James M. Cox Dayton Intl. to Denver Intl., returning Tue, May 12, priced at $319 found 18 hours ago
Wed, Jul 8 - Wed, Jul 22
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$321 Roundtrip, found 1 day ago
$321
Roundtrip
found 1 day ago
Select United flight, departing Wed, Jul 8 from James M. Cox Dayton Intl. to Denver Intl., returning Wed, Jul 22, priced at $321 found 1 day ago
Sun, May 10 - Sat, May 16
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$329 Roundtrip, found 10 hours ago
$329
Roundtrip
found 10 hours ago
Select United flight, departing Sun, May 10 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, May 16, priced at $329 found 10 hours ago
Sat, Jun 20 - Tue, Jun 23
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$329 Roundtrip, found 4 days ago
$329
Roundtrip
found 4 days ago
Select United flight, departing Sat, Jun 20 from James M. Cox Dayton Intl. to Denver Intl., returning Tue, Jun 23, priced at $329 found 4 days ago
Thu, Jun 11 - Sun, Jun 21
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$330 Roundtrip, found 1 day ago
$330
Roundtrip
found 1 day ago
Select United flight, departing Thu, Jun 11 from James M. Cox Dayton Intl. to Denver Intl., returning Sun, Jun 21, priced at $330 found 1 day ago
Wed, Jul 8 - Wed, Jul 22
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$331 Roundtrip, found 1 day ago
$331
Roundtrip
found 1 day ago
Select United flight, departing Wed, Jul 8 from James M. Cox Dayton Intl. to Denver Intl., returning Wed, Jul 22, priced at $331 found 1 day ago
Wed, Jul 8 - Wed, Jul 22
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$336 Roundtrip, found 1 day ago
$336
Roundtrip
found 1 day ago
Select United flight, departing Wed, Jul 8 from James M. Cox Dayton Intl. to Denver Intl., returning Wed, Jul 22, priced at $336 found 1 day ago
Sat, May 2 - Sat, May 9
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$336 Roundtrip, found 1 day ago
$336
Roundtrip
found 1 day ago
Select United flight, departing Sat, May 2 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, May 9, priced at $336 found 1 day ago
Sun, May 10 - Sat, May 16
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$339 Roundtrip, found 10 hours ago
$339
Roundtrip
found 10 hours ago
Select United flight, departing Sun, May 10 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, May 16, priced at $339 found 10 hours ago
Sun, May 10 - Sat, May 16
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$344 Roundtrip, found 10 hours ago
$344
Roundtrip
found 10 hours ago
Select United flight, departing Sun, May 10 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, May 16, priced at $344 found 10 hours ago
Wed, Jul 8 - Wed, Jul 22
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$346 Roundtrip, found 1 day ago
$346
Roundtrip
found 1 day ago
Select United flight, departing Wed, Jul 8 from James M. Cox Dayton Intl. to Denver Intl., returning Wed, Jul 22, priced at $346 found 1 day ago
Fri, Apr 10 - Mon, Apr 13
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$350 Roundtrip, found 2 days ago
$350
Roundtrip
found 2 days ago
Select United flight, departing Fri, Apr 10 from James M. Cox Dayton Intl. to Denver Intl., returning Mon, Apr 13, priced at $350 found 2 days ago
Thu, Jun 11 - Sun, Jun 21
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$353 Roundtrip, found 1 day ago
$353
Roundtrip
found 1 day ago
Select United flight, departing Thu, Jun 11 from James M. Cox Dayton Intl. to Denver Intl., returning Sun, Jun 21, priced at $353 found 1 day ago
Sun, May 10 - Sat, May 16
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$354 Roundtrip, found 10 hours ago
$354
Roundtrip
found 10 hours ago
Select United flight, departing Sun, May 10 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, May 16, priced at $354 found 10 hours ago

Frequently asked questions

What route does flight number UA1521 take?
UA1521 jets between IAD and CLE directly. This trip takes 1 hour and 14 minutes.
How often is UA1521 on time?
United Airlines flight number UA1521 between IAD and Hopkins Intl. Airport (CLE) runs on schedule 91% of the time — so you can relax knowing that you will reach your destination ASAP. If your service is delayed, you're likely to wait approximately 44 minutes. This route has a star rating of 2.75.
What kind of plane is on flight number UA1521?
Get set to cruise the skies aboard a Boeing 737-800 if your flight number is UA1521. Almost all flights from Dulles Intl. Airport to CLE use 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 UA1521 flight with Travelocity, please visit our Customer Service Portal.