Cheap flights from San Francisco to Illinois from $134

The cheapest month to fly to Illinois from San Francisco is in February. Flight prices, which tend to average around $372, are often lower during this time because this is during the off-season. If you aren’t able to travel to Illinois during the month of February, then flying in January is also cheap. Prices for this month can be found on momondo for an average of $378.

The cheapest day to depart from San Francisco to Illinois is on a Wednesday when prices can be found for as low as $454. Flights from San Francisco to Illinois on a Monday will generally be more expensive and average around $597. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from San Francisco to Illinois during this time can be as low as $480. Flights at noon are often more expensive with an average ticket price of $528.

Fly from San Francisco to Chicago Midway for the best San Francisco - Illinois flight prices

You are more likely to see cheaper flights to Illinois from San Francisco when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $437 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from San Francisco for as low as $363 on momondo.

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

Southwest, United Airlines, and Delta are the most popular carriers operating from San Francisco to Illinois

United Airlines, American Airlines and Southwest are the top three most popular airlines that fly to Illinois from San Francisco according to our data. United Airlines is the first choice among our users, with 48% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 7 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

71 flights are operational daily from San Francisco to Illinois as of November 2026. The most popular departure time for this route is 10:00AM, with 38% of flights per day taking off at noon.

The number of flights available between San Francisco and Illinois is 500 per week as of November 2026. The most frequent departure day is Mon, with 18% of weekly flights leaving on this day.