Southwest Airlines SEA TerminalThe Seattle-Tacoma International Airport's Concourse B is where Southwest Airlines SEA Terminal is based (SEA). Travelers will find self-service kiosks, check-in counters, and security screening close to the entrance, among other necessary amenities, in this terminal. It's simple to locate refreshments and last-minute travel necessities before boarding a Southwest flight thanks to Concourse B's numerous dining options, retail establishments, and coffee shops.