$1,258 Cheap Flights from Monrovia (ROB) to St. Louis (STL)

View $1,258 flight on Mon, Dec 29, 2025Opens in a new window

Popular airlines from Monrovia (ROB-Roberts Intl.) to St. Louis Lambert Intl. Airport (STL)

Cheap Flights from Monrovia to St. Louis (ROB-STL)

Prices were available within the past 7 days and start at $1,258 for one-way flights and $1,653 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Fri, Aug 22 - Mon, Aug 25
ROB
Monrovia
STL
St. Louis
$1,653 Roundtrip, found 4 days ago
$1,653
Roundtrip
found 4 days ago
Select American Airlines flight, departing Fri, Aug 22 from Monrovia to St. Louis, returning Mon, Aug 25, priced at $1,653 found 4 days ago
American Airlines
Fri, Aug 22 - Fri, Aug 29
ROB
Monrovia
STL
St. Louis
$1,739 Roundtrip, found 4 days ago
$1,739
Roundtrip
found 4 days ago
Select American Airlines flight, departing Fri, Aug 22 from Monrovia to St. Louis, returning Fri, Aug 29, priced at $1,739 found 4 days ago
American Airlines
Fri, Aug 22 - Wed, Aug 27
ROB
Monrovia
STL
St. Louis
$1,765 Roundtrip, found 4 days ago
$1,765
Roundtrip
found 4 days ago
Select American Airlines flight, departing Fri, Aug 22 from Monrovia to St. Louis, returning Wed, Aug 27, priced at $1,765 found 4 days ago
United
Sun, Aug 31 - Mon, Sep 8
ROB
Monrovia
STL
St. Louis
$1,888 Roundtrip, found 2 days ago
$1,888
Roundtrip
found 2 days ago
Select United flight, departing Sun, Aug 31 from Monrovia to St. Louis, returning Mon, Sep 8, priced at $1,888 found 2 days ago
United
Sun, Aug 31 - Sun, Sep 7
ROB
Monrovia
STL
St. Louis
$1,903 Roundtrip, found 2 days ago
$1,903
Roundtrip
found 2 days ago
Select United flight, departing Sun, Aug 31 from Monrovia to St. Louis, returning Sun, Sep 7, priced at $1,903 found 2 days ago
Brussels Airlines
Tue, Aug 26 - Tue, Sep 2
ROB
Monrovia
STL
St. Louis
$1,983 Roundtrip, found 2 days ago
$1,983
Roundtrip
found 2 days ago
Select Brussels Airlines flight, departing Tue, Aug 26 from Monrovia to St. Louis, returning Tue, Sep 2, priced at $1,983 found 2 days ago
Brussels Airlines
Tue, Aug 26 - Sun, Sep 7
ROB
Monrovia
STL
St. Louis
$2,002 Roundtrip, found 2 days ago
$2,002
Roundtrip
found 2 days ago
Select Brussels Airlines flight, departing Tue, Aug 26 from Monrovia to St. Louis, returning Sun, Sep 7, priced at $2,002 found 2 days ago
United
Sun, Aug 31 - Thu, Sep 4
ROB
Monrovia
STL
St. Louis
$2,023 Roundtrip, found 2 days ago
$2,023
Roundtrip
found 2 days ago
Select United flight, departing Sun, Aug 31 from Monrovia to St. Louis, returning Thu, Sep 4, priced at $2,023 found 2 days ago
Brussels Airlines
Tue, Aug 26 - Thu, Sep 4
ROB
Monrovia
STL
St. Louis
$2,043 Roundtrip, found 2 days ago
$2,043
Roundtrip
found 2 days ago
Select Brussels Airlines flight, departing Tue, Aug 26 from Monrovia to St. Louis, returning Thu, Sep 4, priced at $2,043 found 2 days ago
Ethiopian Airlines
Thu, Aug 28 - Wed, Sep 3
ROB
Monrovia
STL
St. Louis
$2,217 Roundtrip, found 2 days ago
$2,217
Roundtrip
found 2 days ago
Select Ethiopian Airlines flight, departing Thu, Aug 28 from Monrovia to St. Louis, returning Wed, Sep 3, priced at $2,217 found 2 days ago

Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $1,888
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $1,888
Flights from Monrovia (ROB) to St. Louis (STL)
Origin airport
Roberts Intl.
Destination airport
Lambert-St. Louis Intl.
Roundtrip price
$1,653
Distance
5410 mi

Monrovia to St. Louis Flights

The cheapest times to fly from Monrovia to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Monrovia to St. Louis are during the month of August. You can find some of the cheapest flights from Monrovia to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Monrovia to St. Louis

Sunday is one of the best days to book for cheap flights from Monrovia to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Monrovia to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Monrovia to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $1,258 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Monrovia to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Monrovia to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL) cost?
Grab a cheap one-way flight from $1,258 or cheap return flight from $1,653 from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight deals on this route.
What is the cheapest month to fly from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL)?
The cheapest month to fly from ROB to STL is August, when there's less demand. Off-peak months are often when airlines offer better prices between these airports.
What is the cheapest airline that flies from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL)?
To find the cheapest airline that'll fly you from ROB to STL, use Expedia's filter tool. Tailor your search based on what's important to you, such as preferred carriers and ideal departure window. You can then sort your results by "Price (lowest to highest)" to see the cheapest flights first.
How many flights per day from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL)?
You'll have to catch a flight with a layover if you're traveling from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL). There are no daily direct flights on this route. However, simply filter your search to include one or two stops to find an option that works for you.
What day of the week has the most flights from ROB to STL?
You'll usually find Tuesday the quietest day for flights, while Fridays are often the busiest.* However this can vary from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL)?
Choose a flight from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL) that leaves before 3 PM to reduce the risk of delays and cancellations. Departures after this time are on average 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Booking your flight from ROB to STL just before your journey is usually more expensive. However, if there's some wiggle room with your travel times and dates, you could grab a cheap last-minute fare.
Is it cheaper to book a ROB to STL flight and hotel package?
Compared with arranging flights and hotels separately, booking a ROB to STL flight and hotel package with Expedia could lead to significant savings. Better yet, having everything in one easy place takes the hassle out of travel planning. Simply secure your flights and choose from our wide range of hotels, then tailor your trip with other add-ons like tours and car rentals.
Can I cancel or change the date of my flight from Roberts Intl. Airport (ROB) to Lambert-St. Louis Intl. Airport (STL)?
Typically, it's possible to reschedule or cancel your ROB to STL flight. However, if it's been more than 24 hours since booking, additional charges may apply. Check your airline's policies in your itinerary to see what changes are allowed and if any costs are involved. You'll also find more information on our Customer Service portal.

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*Available to One Key members.