American Airlines Flight 1240 Deals & Information (2025/2026)

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American Airlines Flight 1240 Route Deals From $153

The cheapest prices found with in the last 7 days for return flights were $271 and $153 for one-way flights to Lambert-St. Louis Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Wed, Jun 4 - Wed, Jun 11
LAX
Los Angeles Intl.
STL
Lambert-St. Louis Intl.
$271 Roundtrip, found 5 days ago
$271
Roundtrip
found 5 days ago
Select American Airlines flight, departing Wed, Jun 4 from Los Angeles Intl. to Lambert-St. Louis Intl., returning Wed, Jun 11, priced at $271 found 5 days ago
Wed, Jun 4 - Mon, Jun 9
LAX
Los Angeles Intl.
STL
Lambert-St. Louis Intl.
$281 Roundtrip, found 2 days ago
$281
Roundtrip
found 2 days ago
Select American Airlines flight, departing Wed, Jun 4 from Los Angeles Intl. to Lambert-St. Louis Intl., returning Mon, Jun 9, priced at $281 found 2 days ago
Tue, May 20 - Sun, May 25
LAX
Los Angeles Intl.
STL
Lambert-St. Louis Intl.
$331 Roundtrip, found 1 day ago
$331
Roundtrip
found 1 day ago
Select American Airlines flight, departing Tue, May 20 from Los Angeles Intl. to Lambert-St. Louis Intl., returning Sun, May 25, priced at $331 found 1 day ago

Frequently asked questions

What route does flight number AA1240 take?
AA1240 takes a number of routes. The most frequently flown is Sea-Tac Airport to O’Hare Airport, which flies direct. This flight typically takes 4 hours and 21 minutes. That said, there may be other flights with this number that are multi-stop.
How often is AA1240 on time?
American Airlines flight number AA1240 from Seattle, WA Airport (SEA-Seattle - Tacoma Intl.) to ORD touches down according to schedule 93% of the time, so you can relax knowing that you will get to your destination ASAP. In the rare event that it is behind schedule, it is delayed on average by 37 minutes. This flight has a 2.9-star rating.
What kind of plane is on flight number AA1240?
AA1240 is a flight number that is used on many different routes. If you’re booked on the busiest route, SEA to ORD, there’s a strong chance you’ll be cruising aboard a Boeing 737-800.
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 AA1240 flight with Travelocity, please visit our Customer Service Portal.