Yes, you can almost always select or change your seat after booking, but in 2026, your ability to do so for "free" depends on your fare class. If you booked a "Basic Economy" or "Saver" fare, the airline may not let you pick a seat until check-in (24 hours before flight) without paying a fee. For "Standard Economy" or higher, you can log into the airline's app or website, go to "Manage Trip," and view the seat map to make a selection. A major change as of January 27, 2026, is that Southwest Airlines now offers assigned seating; while "Choice" and "Preferred" fares allow selection at booking, those on "Basic" fares will have their seats assigned at check-in if they don't pay an upgrade fee.