Singapore Airlines Limited (SIA) ( , abbreviated 新航; Syarikat Penerbangan Singapura; சிங்கப்பூர் ஏர்லைன்ஸ்) ( ) is the national airline of Singapore. Singapore Airlines operates a hub at Singapore Changi Airport and has a presence in the airline markets of Southeast Asia, East Asia, South Asia, and the competitive "Kangaroo Route" between Europe and Oceania. The company also operates trans-Pacific flights, including two of the world's longest non-stop commercial flights from Singapore to Newark, New Jersey and Los Angeles, California on the Airbus A340. Singapore Airlines is known for being the launch customer of the superjumbo Airbus A380.

SIA has diversified into airline related businesses such as aircraft handling and engineering. Its wholly owned subsidiary, SilkAir, manages regional flights to secondary cities with smaller capacity requirements. Subsidiary Singapore Airlines Cargo operates SIA's dedicated freighter fleet manages the cargo hold capacity in SIA's passenger aircraft. SIA has a 49% shareholding in Virgin Atlantic and has also responded to the threats posed by the low-cost sector by investing a 49% stake in Tiger Airways. Singapore Airlines Limited is the world's second largest carrier by market capitalisation. It ranks amongst the top 15 carriers worldwide in terms of revenue passenger kilometres , is the 8th largest airline in Asia and ranked 6th in the world for international passengers carried.

Singapore Airlines was ranked 17th in Fortune's World’s Most Admired Companies rankings in 2007 ) and has built up a strong brand name as a trendsetter in the aviation industry, particularly in terms of innovation, safety and service excellence, coupled with consistent profitability. It has won numerous awards and is an industry bellwether for aircraft purchases. The airline was Asia's first and the world's third airline to be accredited by IATA with the IOSA (IATA Operations Safety Audit). .