United Flight 4576 Deals & Information (2026/2027)

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United Flight 4576 Route Deals From $98

The cheapest prices found with in the last 7 days for return flights were $119 and $98 for one-way flights to Lambert-St. Louis Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$119 Roundtrip, found 3 hours ago
$119
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $119 found 3 hours ago
Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$150 Roundtrip, found 3 hours ago
$150
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $150 found 3 hours ago
Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$152 Roundtrip, found 3 hours ago
$152
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $152 found 3 hours ago
Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$178 Roundtrip, found 3 hours ago
$178
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $178 found 3 hours ago
Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$183 Roundtrip, found 3 hours ago
$183
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $183 found 3 hours ago
Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$185 Roundtrip, found 3 hours ago
$185
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $185 found 3 hours ago
Tue, May 19 - Wed, Jun 3
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$188 Roundtrip, found 3 hours ago
$188
Roundtrip
found 3 hours ago
Select United flight, departing Tue, May 19 from O'Hare Intl. to Lambert-St. Louis Intl., returning Wed, Jun 3, priced at $188 found 3 hours ago
Sat, May 2 - Tue, May 5
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$192 Roundtrip, found 4 days ago
$192
Roundtrip
found 4 days ago
Select United flight, departing Sat, May 2 from O'Hare Intl. to Lambert-St. Louis Intl., returning Tue, May 5, priced at $192 found 4 days ago
Mon, Apr 27 - Thu, Apr 30
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$199 Roundtrip, found 5 days ago
$199
Roundtrip
found 5 days ago
Select United flight, departing Mon, Apr 27 from O'Hare Intl. to Lambert-St. Louis Intl., returning Thu, Apr 30, priced at $199 found 5 days ago

Frequently asked questions

What route does flight number UA4576 take?
Flight number UA4576 operates non-stop from ACK to Newark, NJ Airport (EWR-Liberty Intl.). During this trip, you'll be in the air for approximately 1 hour and 40 minutes. Consider booking ahead to lock in your favorite seat.
What kind of plane is on flight number UA4576?
There's every chance you'll be cruising aboard the Canadair (Bombardier) Regional Jet 550 if you have a seat on flight UA4576. Typically, this flight leaves from Nantucket, MA Airport (ACK-Nantucket Memorial) and comes in to land at EWR.
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 UA4576 flight with Travelocity, please visit our Customer Service Portal.