$161 Cheap Southwest Airlines flights Chicago (ORD) to San Juan (SJU)

Landing cheap one-way Southwest Airlines flights from ORD to SJU from $161 on Expedia is a breeze — just filter by "Price (lowest to highest)." Or check out our affordable return fares from $349 for your next adventure.**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.

Search for Southwest Airlines flights from ORD to SJU about one month before you want to leave. The most affordable time to book an international flight is usually 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. Regardless of itinerary or fare class, the best day to book international airfare is usually Sunday. Friday is often the most expensive. Travelers who book on a Sunday can save 17% on average compared to those who book on a Friday.**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 find the earliest departures from ORD to SJU with Southwest Airlines, filter your search by "Morning" and "Early Morning." Choosing an early flight generally means you're less likely to experience 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.