Lot Victor Diffey (21 March 1877 – 23 February 1952) was an Australian politician.
He was born in Tarrawingee to farmer Dan Diffey and Hannah Dunkley.
He became a farmer at Everton and on 9 November 1903 married Jessie Catherine Mitchell, with whom he had five children; he would later marry Eveline May Hunt around 1949.
A founding member of the Country Party who served on its council from 1919 to 1924, he was elected to the Victorian Legislative Assembly in 1929 for Wangaratta and Ovens.
In 1950 Diffey moved to Cheltenham, and he died in Brighton in 1952.