$71 Cheap Spirit Airlines flights Boston (BOS) to Chicago (ORD)

You can find affordable round-trip Spirit Airlines flights from $167 from BOS to ORD by organizing your results from "Price (lowest to highest)" on Expedia. Or search for deals from $71 for a one-way trip.**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.

For cheap Spirit Airlines fares from Logan Intl. Airport (BOS) to O'Hare Intl. Airport (ORD), start searching one to three months before your intended departure. Securing domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also affect the price you pay. Sunday is typically the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your journey on a Sunday.**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.

Find Spirit Airlines's earliest flights from BOS to ORD by selecting our "Morning" and "Early Morning" filters. Not only will you get to your destination sooner, early departures also experience 20% fewer cancellations.**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.

A rewarding loyalty program and the chance to rack up points through Free Spirit are the start of the reasons to jet off from BOS to ORD with Spirit Airlines. Plus, when you join our One Key™ program, you can receive OneKeyCash™* alongside Spirit Airlines's loyalty program earnings. It's yours to spend on future bookings.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.