Book 6-8 weeks ahead for the best fares on the BCN to ORD route.
Tuesday and Wednesday departures are typically 15-20% cheaper.
This is a long-haul flight (~8h 21m). Consider comfort upgrades or stopover options.
Compare 2 airlines on this route: AA, UA.
Check visa requirements for your destination well in advance.

Route details All flights from BCN All flights from ORD