The 1965–66 BBC2 Floodlit Trophy was the inaugural season of the BBC2 Floodlit Trophy competition. Castleford won the trophy by beating St. Helens with a score of 4–0. The match was played at Knowsley Road, Eccleston, St Helens, Merseyside. The attendance was 11,510 and receipts were £3,548. This was to be the first of Castleford's three victories in successive seasons in the first three Floodlit competitions.