Ryanair Holdings PLC is an Irish ultra low-cost carrier group headquartered in Swords, Dublin, Ireland. The company includes the subsidiaries Ryanair DACTooltip Designated activity company, Malta Air, Buzz, Lauda Europe and Ryanair UK. Ryanair DAC, the oldest airline of the group, was founded in 1984. Ryanair Holdings was established in 1996 as a holding company for Ryanair with the two companies having the same board of directors and executive officers. In 2019 the transition began from the airline Ryanair and its subsidiaries into separate sister airlines under the holding company. Later in 2019 Malta Air joined Ryanair Holdings.

A low-cost carrier (LCC) or low-cost airline, also called no-frills, budget or discount carrier or airline, is an airline that is operated with an emphasis on minimizing operating costs. It sacrifices certain traditional airline luxuries, for cheaper fares. To make up for revenue lost in decreased ticket prices, the airline may charge extra fees such as for carry-on baggage. As of April 2020, the world's largest low-cost carrier is Southwest Airlines, which operates primarily in the United States, as well as in some surrounding areas.