Sir Walter Reuben Preston (20 September 1875 – 6 July 1946) was a Conservative Party politician.
At the 1918 general election, he was elected as Member of Parliament for the Mile End constituency in the East End of London. He lost the seat at the 1923 general election to the Labour Party candidate John Scurr.
He returned to Parliament at a by-election in September 1928 for the Cheltenham constituency, and held the seat until he resigned from the House of Commons in 1937.
Walter Reuben Preston was an engineer. He has 35 patents and some of these were obtained jointly with well-known locomotive engineers, such as Richard Deeley. Details of the patents can be found at Espacenet.
Educated at Bedford School, Preston married Ella Margaret Morris (born 7 September 1877, died 28 January 1963) at Hayes between April and June 1900. There are memorial inscriptions to both at Holy Trinity Church, Long Newnton, near Tetbury, Gloucestershire.