The Handley Page H.P.42 and H.P.45 were four-engine biplane airliners designed and manufactured by British aviation company Handley Page, based in Radlett, Hertfordshire. They held the distinction of being the largest airliners in regular use in the world upon the type's introduction in 1931.

Handley Page Limited was a British aerospace manufacturer. Founded by Frederick Handley Page in 1909, it was the United Kingdom's first publicly traded aircraft manufacturing company. It went into voluntary liquidation and ceased to exist in 1970. The company, based at Radlett Aerodrome in Hertfordshire, was noted for its pioneering role in aviation history and for producing heavy bombers and large airliners.