Clement Francis Cornwall (June 18, 1836 – February 15, 1910) was a Canadian parliamentarian and the third Lieutenant Governor of British Columbia.

In 1864 Cornwall was elected to represent the Hope-Yale-Lytton riding for the newly created colonial Legislative Assembly , and was also a member of the same body in 1871 during the period in which British Columbia joined Canadian confederation.

He was engaged in "rural pursuits" – the life of a gentleman rancher – from the time of his retirement until September 17, 1889, when he was appointed to the bench as Judge of the County Court of Cariboo, also receiving the title of Stipendiary Magistrate in the same year.

In partnership with his brother Henry P. Cornwall, he managed a ranching operation which for many years was the province's largest supplier of livestock.

Ashcroft became one of the main horse-racing venues in the province at a time when that was the number-one sport, and Cornwall took a prominent part in their organization.