Cheap Flights to Chicago Compare & Book Affordable Airfare
About Chicago
As the third-largest city in America, Chicago (CHI) serves as the cultural and financial hub of the American Midwest region in the state of Illinois, along the southwestern part of Lake Michigan. Known for its famous skyline, deep dish pizza, music, and fanatical sporting tradition, the city attracts tens of millions of tourists annually. The presence of two international airports at O’Hare (ORD) and Midway (MDW) makes it the most easily accessible city via air travel across the country.
- Cheapest Month to Fly: January (followed by February and early March)
- Optimal Booking Window: 21 to 42 days before departure
- Cheapest Day of the Week to Fly: Tuesday (mid-week pricing dips consistently below weekend averages)
- Most Budget-Friendly Airline: Frontier Airlines or Spirit Airlines (ultra-low-cost); Southwest Airlines (for flexible fare value and no change fees)
Chicago Airports
Chicago has two primary airports facilitating easy global travel without any hurdles, making travel smoother.
When Is the Best Time to Book Cheap Flights to Chicago?
According to multi-year data, CHI offers its best price period in January and February, due to the drop in travel demand post-holiday season as carriers slash prices to get rid of unused seats at both ORD and MDW. In a second-best period, travelers can secure deals in late August and early September, which follow the summer holiday traffic period and precede autumn conferences that will drive business demand again.
It is advisable to steer clear of bookings in the months of late November through early January, as well as the week surrounding St. Patrick's Day. Chicago hosts its biggest tourist influx around St. Patrick's Day, which spikes prices citywide across both airports. The spring break period, as well as Fourth of July weekend, will also be high in terms of airfares.
Comparison of Airlines, Policy, and Options for Chicago
One of the most strategically important cities in terms of connections in the USA is Chicago. This table reflects the cross-section of airfares offered to this destination across several airline segments:
American Airlines
- Policy regarding carry-on baggage: Personal item only for Basic Economy; include carry-on for all other fares
- Ideal for travelers leaving from the ORD hub and requiring access to many different domestic and international connections
United Airlines
- Policy regarding carry-on baggage: Personal item only for Basic Economy; include carry-on for all other fares
- Ideal for ORD travelers as well as travelers going through the Star Alliance route network based out of Chicago for international travel
Southwest Airlines
- Policy regarding carry-on baggage: Free 2 checked bags and no Basic Economy fare option available
- Ideal for travelers leaving from MDW who would like extensive refund, change, and cancellation policies without any additional fee
Frontier Airlines
- Policy regarding carry-on baggage: Personal item only, with strict enforcement at the time of boarding
- Ideal for economical travelers leaving from ORD with originations in Sunbelt and Southeastern hub airports
Spirit Airlines
- Policy regarding carry-on baggage: Personal item only, with strict size enforcement and overhead bin fees charged separately
- Ideal for super-economical travelers leaving from MDW and ORD, connecting from Florida, Texas, or northeastern cities
Hidden Fee Alert: What To Do Before Booking
Chicago is perhaps the city with the highest levels of hidden costs when it comes to domestic flights within America. The variations in Basic Economy limitations are quite significant across carriers servicing Chicago ORD and MDW airports.
- Spirit and Frontier: Fees for carry-on bags: Fares offered by Spirit and Frontier in Basic Economy come with the limitation that only a personal item can be taken in the overhead compartment, but it must be paid to gain access to the bin. Non-conforming luggage brought to the gate would cost approximately $65-$99 as an extra charge.
- No seat assignment on Basic Economy on American Airlines and United: Tickets purchased in Basic Economy on American Airlines and United Airlines flying to ORD have no seat assignment privileges.
- Two free checked bags with Southwest Airlines at MDW Airport: Southwest Airlines previously offered two free checked bags for all passengers, but as of 2026, checked baggage fees apply to many fare types. Travelers with elite status, qualifying fare bundles, or eligible Southwest credit cards may still receive free checked baggage benefits.
- Changes and Cancellation Costs for Basic Economy Flights into Chicago: American, United, Delta, Frontier, and Spirit do not allow any changes or cancellations in case of their basic economy fares into Chicago.
Frequently Asked Questions
Here are some of the questions visitors commonly ask before travelling:
