The Airbus A321neo is a single-aisle airliner created by Airbus. The A321neo is developed from the Airbus A321 and Airbus A320neo family. It is the longest stretched fuselage of Airbus's A320 series, and the newest version of the A321, with the original A321ceo entering service in 1994 with Lufthansa. It typically seats 180 to 220 passengers in a two-class configuration, with up to 244 passengers in a high-density arrangement.

A narrow-body aircraft or single-aisle aircraft is an airliner arranged along a single aisle, permitting up to 6-abreast seating in a cabin less than 4 metres (13 ft) in width. In contrast, a wide-body aircraft is a larger airliner usually configured with multiple aisles and a fuselage diameter of more than 5 metres (16 ft), allowing at least seven-abreast seating and often more travel classes.