Cheap flights from Pennsylvania to Illinois from $90

The cheapest month to fly to Illinois from Pennsylvania is in January. Flight prices, which tend to average around $301, 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 January, then flying in December is also cheap. Prices for this month can be found on momondo for an average of $314.

The cheapest day to depart from Pennsylvania to Illinois is on a Friday when prices can be found for as low as $378. Flights from Pennsylvania to Illinois on a Sunday will generally be more expensive and average around $519. 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 Pennsylvania to Illinois during this time can be as low as $358. Flights at noon are often more expensive with an average ticket price of $438.

Fly from Philadelphia to Chicago O'Hare Intl for the best Pennsylvania - Illinois flight prices

You are more likely to see cheaper flights to Illinois from Pennsylvania when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $328 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Pennsylvania for as low as $279 on momondo.

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

Frontier, Southwest, and United Airlines are the most popular carriers operating from Pennsylvania to Illinois

United Airlines, American Airlines and Frontier are the top three most popular airlines that fly to Illinois from Pennsylvania according to our data. United Airlines is the first choice among our users, with 42% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 5 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

The number of flights available between Pennsylvania and Illinois is 128 per day as of November 2026. The most frequent departure time is 4:00PM, with 43% of daily flights leaving in the afternoon.

As of November 2026, there are 900 flights per week flying from Pennsylvania to Illinois. The most common day of the week flights depart is Fri, with 16% of flights taking off on this day.