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Cheap flights from St. Louis to Chicago O'Hare Intl Airport

STL — ORD
18 Oct — 25 Oct1
1 adult
1 adult, Economy

Cheapflights Tip: The best prices from Lambert-St Louis to Chicago O'Hare Intl are usually found in September or April, booked 75 days in advance, depart on a Wednesday or Tuesday and return on a Monday

Cheap flight deals from St. Louis to O'Hare Intl

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to O'Hare Intl (ORD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 18 September 2025.

Popular in

July

Cheapest in

September

Average price

£158

Good round-trip deal

£496 or less

Good one-way deal

£163 or less
Highest demand for flights based on searches. 6% potential increase in price (£10 potential increase over avg. return price).
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Cheapest flight prices on average. 2% potential price decrease (£4 potential savings vs. average return price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Lambert-St Louis to Chicago O'Hare Intl.
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Price to beat on a one-way flight from Lambert-St Louis to Chicago O'Hare Intl.
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Best time to book a flight from St. Louis to O'Hare Intl

Have a flexible travel schedule? Discover the best time to fly to O'Hare Intl from St. Louis with our price prediction graph.
Estimated return price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Chicago O'Hare Intl Airport

How far ahead should I book a flight from St. Louis to Chicago O'Hare Intl Airport?

Use this chart to determine the optimal time to book a return flight from St. Louis to O'Hare Intl. Price data was last updated on 12 September 2025.

The best time to book flights from St. Louis to Chicago O'Hare Intl Airport is 75 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from St. Louis to Chicago O'Hare Intl Airport?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Chicago O'Hare Intl Airport (average of £595). Flying from St. Louis to Chicago O'Hare Intl Airport in July is currently the most expensive (average of £843). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to ORD?

Find hourly flight availability from St. Louis to O'Hare Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 18 September 2025.

A simple way to save on the total cost of your ticket is to fly from St. Louis to Chicago O'Hare Intl Airport in the morning. If you’re flexible enough to do this you can expect to save up to 40% on your trip compared to booking a flight at midday.

What is the cheapest day to fly from St. Louis to Chicago O'Hare Intl Airport?

Use this chart to determine the cheapest time to fly return from St. Louis to O'Hare Intl. Price data was last updated on 22 June 2025.

Travellers seeking maximum savings on their St. Louis to Chicago O'Hare Intl Airport flight should consider departing on Thursday evenings when fares are most often at their lowest. Monday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to O'Hare Intl. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to Chicago O'Hare Intl?

    For a flight from St. Louis to Chicago O'Hare Intl, you will be flying from Lambert-St Louis. Lambert-St Louis (STL) is just 12.7 mi from the center of the city. Lambert-St Louis is the only St. Louis airport and it handles 61 outbound flights to Chicago O'Hare Intl per day. 0 airlines have flights to Chicago O'Hare Intl from Lambert-St Louis on a regular basis.

  • What are the most reliable airlines from St. Louis to Chicago O'Hare Intl Airport?

    Consider Cathay Pacific (89%), Japan Airlines (80%) or Copa Airlines (78%) when booking your flight. These represent the most reliable airlines when flying from St. Louis to Chicago O'Hare Intl Airport.

  • Can I find deals for flights from St. Louis to O'Hare Intl that include hotel bookings?

    Yes. In addition to deals on St. Louis to O'Hare Intl flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to O'Hare Intl?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to O'Hare Intl.

  • Can I find deals for business class flights from St. Louis to O'Hare Intl?

    Yes. Cheapflights offers flight deals from St. Louis to O'Hare Intl by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from St. Louis to Chicago O'Hare Intl Airport?

    Currently, January is the cheapest month in which you can book a flight from St. Louis to Chicago O'Hare Intl Airport (average of £595). Flying from St. Louis to Chicago O'Hare Intl Airport in July is currently the most expensive (average of £843). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near Chicago O'Hare Intl Airport?

Book flights to Chicago O'Hare Intl Airport if you plan to visit one of these locations
Downers Grove
Elk Grove Village
Rosemont

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Can Cheapflights notify me if prices for flights from St. Louis to O'Hare Intl become cheaper?

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