Sir Maurice Alberic Twisleton-Wykeham-Fiennes (1 March 1907 – 14 September 1994) was an English industrialist. He was educated at the independent Repton School in the village of Repton in Derbyshire and at Armstrong College in Newcastle-upon-Tyne.
He was chairman of Davy-Ashmore in Sheffield and achieved success as a producer of high quality British steel. He was made a knight by Harold Wilson in recognition of his contributions to British engineering.
Fiennes was the son of Alberic Arthur Twisleton-Wykeham-Fiennes, and his wife, Gertrude Theodosia Pomeroy (née Colley), and great-grandson of Frederick Benjamin Twisleton-Wykeham-Fiennes, 16th Baron Saye and Sele. He married Sylvia Joan Finlay, with whom he had five children including photographer Mark Fiennes. He was the grandfather of actors Ralph Fiennes and Joseph Fiennes.