Cheap flights from Illinois to Key West from $93

In general, August is the cheapest month to fly from Illinois to Key West. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $368. If you are unable to visit Key West during the month of August, then departing from Illinois during the month July is also very affordable. Most momondo users find prices during this month for around $377.

On average, the least expensive day to fly to Key West from Illinois is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as $360. However, this price may fluctuate depending on the airline, the season, and holidays. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Illinois to Key West for around $513.

According to our data, the cheapest time of day to fly to Key West is in the morning. momondo users have found flights departing from Illinois to Key West in the morning for as low as $447. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights to Key West are more costly in the afternoon, with an average ticket price of $449. Departure times in the afternoon fall within the peak daily travel times, which is why tickets can be more expensive.

Fly from Chicago O'Hare Intl to Key West for the best Illinois - Key West flight prices

You are more likely to see cheaper flights to Key West from Illinois when booking weeks ahead of your departure date. In general, you can expect to find flights to Key West for around $425 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Key West from Illinois for as low as $372 on momondo.

There are 4 cabin classes available to choose from on Illinois to Key West flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Allegiant Air, United Airlines, and American Airlines are the most popular carriers operating from Illinois to Key West

American Airlines, United Airlines and Delta are the top three most popular airlines that fly to Key West from Illinois according to our data. American Airlines is the first choice among our users, with 58% of people opting to fly with this airline when traveling to Key West. Keep in mind that there are 3 different airlines that fly to Key West on a routine basis, so you have a few additional options to choose from.

As of September 2026, there are 2 flights per week flying from Illinois to Key West. The most common day of the week flights depart is Mon, with 50% of flights taking off on this day.

If you’re flying from a popular airport in Illinois, such as Chicago or Peoria, and flying into Key West, then you can expect flight times to average 3h 59m and 5h 06m, respectively.