United Flight 4576 Deals & Information (2026/2027)

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United Flight 4576 Route Deals From $73

The cheapest prices found with in the last 7 days for return flights were $91 and $73 for one-way flights to Lambert-St. Louis Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Wed, Apr 22 - Sat, Apr 25
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$91 Roundtrip, found 2 days ago
$91
Roundtrip
found 2 days ago
Select United flight, departing Wed, Apr 22 from O'Hare Intl. to Lambert-St. Louis Intl., returning Sat, Apr 25, priced at $91 found 2 days ago
Wed, Apr 22 - Sat, Apr 25
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$124 Roundtrip, found 2 days ago
$124
Roundtrip
found 2 days ago
Select United flight, departing Wed, Apr 22 from O'Hare Intl. to Lambert-St. Louis Intl., returning Sat, Apr 25, priced at $124 found 2 days ago
Mon, Apr 6 - Tue, Apr 7
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$138 Roundtrip, found 2 days ago
$138
Roundtrip
found 2 days ago
Select United flight, departing Mon, Apr 6 from O'Hare Intl. to Lambert-St. Louis Intl., returning Tue, Apr 7, priced at $138 found 2 days ago
Wed, Apr 22 - Sat, Apr 25
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$152 Roundtrip, found 2 days ago
$152
Roundtrip
found 2 days ago
Select United flight, departing Wed, Apr 22 from O'Hare Intl. to Lambert-St. Louis Intl., returning Sat, Apr 25, priced at $152 found 2 days ago
Sat, May 16 - Mon, May 18
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$187 Roundtrip, found 10 hours ago
$187
Roundtrip
found 10 hours ago
Select United flight, departing Sat, May 16 from O'Hare Intl. to Lambert-St. Louis Intl., returning Mon, May 18, priced at $187 found 10 hours ago
Sat, May 16 - Mon, May 18
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$190 Roundtrip, found 10 hours ago
$190
Roundtrip
found 10 hours ago
Select United flight, departing Sat, May 16 from O'Hare Intl. to Lambert-St. Louis Intl., returning Mon, May 18, priced at $190 found 10 hours ago
Sat, May 16 - Mon, May 18
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$194 Roundtrip, found 10 hours ago
$194
Roundtrip
found 10 hours ago
Select United flight, departing Sat, May 16 from O'Hare Intl. to Lambert-St. Louis Intl., returning Mon, May 18, priced at $194 found 10 hours ago
Sat, May 16 - Mon, May 18
ORD
O'Hare Intl.
STL
Lambert-St. Louis Intl.
$199 Roundtrip, found 10 hours ago
$199
Roundtrip
found 10 hours ago
Select United flight, departing Sat, May 16 from O'Hare Intl. to Lambert-St. Louis Intl., returning Mon, May 18, priced at $199 found 10 hours 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.