An airline seat is a seat on an airliner in which passengers are accommodated for the duration of the journey. Such seats are usually arranged in rows running across the airplane's fuselage. A diagram of such seats in an aircraft is called an aircraft seat map.

Economy class, also called third class, coach class, steerage, or to distinguish it from the slightly more expensive premium economy class, standard economy class or budget economy class, is the lowest travel class of seating in air travel, rail travel, and sometimes ferry or maritime travel. Historically, this travel class has been called tourist class or third class on ocean liners.