Cheap flights from Chicago to Key West from $109

In general, February is the cheapest month to fly from Chicago to Key West. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $104. If you are unable to visit Key West during the month of February, then departing from Chicago during the month May is also very affordable. Most momondo users find prices during this month for around $136.

On average, the least expensive day to fly to Key West from Chicago is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as $351. 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 Chicago to Key West for around $519.

According to our data, the cheapest time of day to fly to Key West is in the afternoon. momondo users have found flights departing from Chicago to Key West in the afternoon for as low as $449. 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 morning, with an average ticket price of $462. Departure times in the morning 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 Chicago - Key West flight prices

You are more likely to see cheaper flights to Key West from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to Key West for around $434 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Key West from Chicago for as low as $368 on momondo.

No. A direct flight is the cheapest option for a flight between Chicago to Key West.

As of May 2026, prices for Chicago to Key West flights are approximately 24% cheaper when compared to flights at the same time last year.

Allegiant Air is the most popular carrier operating from Chicago to Key West

American Airlines, United Airlines and Delta are the top three most popular airlines that fly to Key West from Chicago according to our data. American Airlines is the first choice among our users, with 55% of people opting to fly with this airline when traveling to Key West. Keep in mind that there are 4 different airlines that fly to Key West on a routine basis, so you have a few additional options to choose from.

Fort Lauderdale (FLL) was the most common stop: 60% of momondo users choosing 1-stop flights on this route connected there.

Flights via Atlanta (ATL) offer the lowest average round-trip price of $196.

Flights connecting via Atlanta (ATL) have the shortest average one-way travel time: 4h 54m.

Atlanta (ATL) has the shortest average layover time for this route: 1h 44m.

As of May 2026, there are 3 flights per day flying from Chicago to Key West. The most common time of day flights depart is 10:00AM, with 77% of flights taking off at noon.

The number of flights available between Chicago and Key West is 23 per week as of May 2026. The most frequent departure day is Mon, with 17% of weekly flights leaving on this day.