$74 Cheap Frontier Airlines flights San Diego (SAN) to Chicago (ORD)

Make use of the “Price (lowest to highest)” filter on Expedia to look for cheap Frontier Airlines return flights from $134 from SAN to ORD. Affordable one-way options from $74 are also available.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

January is one of the cheapest months to travel to Chicago with Frontier Airlines. You could also find fantastic deals on return and one-way tickets in February.

Search for affordable Frontier Airlines flights from San Diego Intl. Airport (SAN) to O’Hare Intl. Airport (ORD) one to three months before your departure day. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. No matter the fare type and journey, the ideal day to book a domestic flight is usually Sunday and the most expensive day is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book on a Monday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC’s global airline sales database.

To see if there’s a direct route from SAN to ORD with Frontier Airlines or any other airlines, use our “Nonstop” filter when looking for tickets.

To find the earliest departure from SAN to ORD with Frontier Airlines, filter your search by “Early Morning” and “Morning.” Booking an early flight usually means cancellations are less likely.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.

Frontier Airlines flights from San Diego Intl. Airport (SAN) to Chicago come in to land at O’Hare Intl. Airport (ORD). This is the main gateway to this destination.

Fly from SAN to ORD with Frontier Airlines and look forward to a host of benefits starting with a rewarding loyalty program. When booking through Expedia as a Frontier Miles and One Key™ member, you can also earn OneKeyCash™* to redeem on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

Changes are often free within 24 hours of booking, but your airline may charge a fee after that time. For more details about altering your flights, head to your “Trips,” select your flight and click on “Manage Booking.” If you want the flexibility to change your plans without being charged, check the “Changes included” and “No cancel fee” filters when organizing your next getaway.