Imperial Airways, a UK carrier which operated from 1924 to 1939 before merging with British Overseas Airways Corporation (BOAC) was an IFE innovator. In April 1925, on board a Handley Page W8f (named City of Washington), the airline screened the first inflight film for passengers on a scheduled flight. This footage shows passengers enjoying watching The Lost World on the London-Paris route.
Trivia: The first in-flight movie was shown in 1921 on Aeromarine Airways (a US airline that operated from 1920 to 1924). The airline showed a promotional film called Howdy Chicago to its passengers via a projector as the 11-passenger Curtis F5L amphibious airplane flew around Chicago during the Parade of Progress Exposition.