United Flight AA721 Deals & Information (2025/2026)

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United Flight 721 Route Deals From $70

The cheapest prices found with in the last 7 days for return flights were $137 and $70 for one-way flights to Logan Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Fri, Oct 24 - Fri, Oct 31
ORD
O'Hare Intl.
BOS
Logan Intl.
$137 Roundtrip, found 9 hours ago
$137
Roundtrip
found 9 hours ago
Select United flight, departing Fri, Oct 24 from O'Hare Intl. to Logan Intl., returning Fri, Oct 31, priced at $137 found 9 hours ago
Wed, Sep 24 - Sun, Sep 28
ORD
O'Hare Intl.
BOS
Logan Intl.
$145 Roundtrip, found 16 hours ago
$145
Roundtrip
found 16 hours ago
Select United flight, departing Wed, Sep 24 from O'Hare Intl. to Logan Intl., returning Sun, Sep 28, priced at $145 found 16 hours ago
Tue, Sep 30 - Sat, Oct 4
ORD
O'Hare Intl.
BOS
Logan Intl.
$149 Roundtrip, found 3 days ago
$149
Roundtrip
found 3 days ago
Select United flight, departing Tue, Sep 30 from O'Hare Intl. to Logan Intl., returning Sat, Oct 4, priced at $149 found 3 days ago
Sun, Aug 31 - Tue, Sep 2
ORD
O'Hare Intl.
BOS
Logan Intl.
$150 Roundtrip, found 3 hours ago
$150
Roundtrip
found 3 hours ago
Select United flight, departing Sun, Aug 31 from O'Hare Intl. to Logan Intl., returning Tue, Sep 2, priced at $150 found 3 hours ago
Thu, Jul 24 - Mon, Jul 28
ORD
O'Hare Intl.
BOS
Logan Intl.
$158 Roundtrip, found 4 hours ago
$158
Roundtrip
found 4 hours ago
Select United flight, departing Thu, Jul 24 from O'Hare Intl. to Logan Intl., returning Mon, Jul 28, priced at $158 found 4 hours ago
Fri, Oct 24 - Fri, Oct 31
ORD
O'Hare Intl.
BOS
Logan Intl.
$165 Roundtrip, found 9 hours ago
$165
Roundtrip
found 9 hours ago
Select United flight, departing Fri, Oct 24 from O'Hare Intl. to Logan Intl., returning Fri, Oct 31, priced at $165 found 9 hours ago

Frequently asked questions

What route does flight number UA721 take?
UA721 serves multiple routes, but the most common is between Sacramento, CA Airport (SMF-Sacramento Intl.) and IAH. If your flight goes direct, you'll land in around 3 hours and 37 minutes. Multi-stop flights can also use this number, as can services on other routes.
What terminal does UA721 fly out of?
If you're booked on a flight from SMF, there's a good chance you'll board the aircraft from Terminal A. The most traveled route for UA721 is SMF to Houston Airport, which is a direct flight.
What kind of plane is on flight number UA721?
There's every chance you'll be aboard a Boeing 737-800 if you've booked a fare from Sacramento Airport to George Bush Intercontinental Airport (IAH), the most popular route for flight number UA721.
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 UA721 flight with Travelocity, please visit our Customer Service Portal.