United Flight 1521 Deals & Information (2026/2027)

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United Flight 1521 Route Deals From $254

The cheapest prices found with in the last 7 days for return flights were $255 and $254 for one-way flights to Denver Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, Apr 14 - Sat, Apr 18
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$255 Roundtrip, found 4 days ago
$255
Roundtrip
found 4 days ago
Select United flight, departing Tue, Apr 14 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, Apr 18, priced at $255 found 4 days ago
Fri, Apr 24 - Mon, Apr 27
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$258 Roundtrip, found 4 days ago
$258
Roundtrip
found 4 days ago
Select United flight, departing Fri, Apr 24 from James M. Cox Dayton Intl. to Denver Intl., returning Mon, Apr 27, priced at $258 found 4 days ago
Wed, Jun 10 - Tue, Jun 16
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$259 Roundtrip, found 4 days ago
$259
Roundtrip
found 4 days ago
Select United flight, departing Wed, Jun 10 from James M. Cox Dayton Intl. to Denver Intl., returning Tue, Jun 16, priced at $259 found 4 days ago
Thu, Apr 9 - Sun, Apr 12
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$274 Roundtrip, found 4 days ago
$274
Roundtrip
found 4 days ago
Select United flight, departing Thu, Apr 9 from James M. Cox Dayton Intl. to Denver Intl., returning Sun, Apr 12, priced at $274 found 4 days ago
Thu, Jun 4 - Tue, Jun 9
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$284 Roundtrip, found 5 days ago
$284
Roundtrip
found 5 days ago
Select United flight, departing Thu, Jun 4 from James M. Cox Dayton Intl. to Denver Intl., returning Tue, Jun 9, priced at $284 found 5 days ago
Wed, Jun 10 - Tue, Jun 16
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$287 Roundtrip, found 4 days ago
$287
Roundtrip
found 4 days ago
Select United flight, departing Wed, Jun 10 from James M. Cox Dayton Intl. to Denver Intl., returning Tue, Jun 16, priced at $287 found 4 days ago
Fri, Apr 24 - Sun, Apr 26
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$290 Roundtrip, found 6 days ago
$290
Roundtrip
found 6 days ago
Select United flight, departing Fri, Apr 24 from James M. Cox Dayton Intl. to Denver Intl., returning Sun, Apr 26, priced at $290 found 6 days ago
Tue, Apr 14 - Sat, Apr 18
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$295 Roundtrip, found 4 days ago
$295
Roundtrip
found 4 days ago
Select United flight, departing Tue, Apr 14 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, Apr 18, priced at $295 found 4 days ago
Wed, Jul 8 - Wed, Jul 22
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$296 Roundtrip, found 5 hours ago
$296
Roundtrip
found 5 hours ago
Select United flight, departing Wed, Jul 8 from James M. Cox Dayton Intl. to Denver Intl., returning Wed, Jul 22, priced at $296 found 5 hours ago
Tue, Apr 7 - Mon, Apr 13
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$297 Roundtrip, found 4 days ago
$297
Roundtrip
found 4 days ago
Select United flight, departing Tue, Apr 7 from James M. Cox Dayton Intl. to Denver Intl., returning Mon, Apr 13, priced at $297 found 4 days ago
Thu, Sep 24 - Thu, Oct 1
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$312 Roundtrip, found 3 hours ago
$312
Roundtrip
found 3 hours ago
Select United flight, departing Thu, Sep 24 from James M. Cox Dayton Intl. to Denver Intl., returning Thu, Oct 1, priced at $312 found 3 hours ago
Wed, Sep 9 - Mon, Sep 14
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$316 Roundtrip, found 2 days ago
$316
Roundtrip
found 2 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 2 days ago
Tue, Apr 21 - Sat, Apr 25
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$318 Roundtrip, found 4 hours ago
$318
Roundtrip
found 4 hours ago
Select United flight, departing Tue, Apr 21 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, Apr 25, priced at $318 found 4 hours ago
Tue, Apr 21 - Sat, Apr 25
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$321 Roundtrip, found 4 hours ago
$321
Roundtrip
found 4 hours ago
Select United flight, departing Tue, Apr 21 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, Apr 25, priced at $321 found 4 hours ago
Wed, Jul 8 - Wed, Jul 22
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$324 Roundtrip, found 5 hours ago
$324
Roundtrip
found 5 hours ago
Select United flight, departing Wed, Jul 8 from James M. Cox Dayton Intl. to Denver Intl., returning Wed, Jul 22, priced at $324 found 5 hours ago
Tue, Apr 21 - Sat, Apr 25
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$328 Roundtrip, found 4 hours ago
$328
Roundtrip
found 4 hours ago
Select United flight, departing Tue, Apr 21 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, Apr 25, priced at $328 found 4 hours ago
Sat, Jun 20 - Tue, Jun 23
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$329 Roundtrip, found 8 hours ago
$329
Roundtrip
found 8 hours 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 8 hours ago
Tue, Apr 21 - Sat, Apr 25
DAY
James M. Cox Dayton Intl.
DEN
Denver Intl.
$330 Roundtrip, found 4 hours ago
$330
Roundtrip
found 4 hours ago
Select United flight, departing Tue, Apr 21 from James M. Cox Dayton Intl. to Denver Intl., returning Sat, Apr 25, priced at $330 found 4 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.