There is one Commonwealth War Grave in St Allen Churchyard:

See: https://www.cwgc.org/visit-us/find-cemeteries-memorials/cemetery-details/37062/ST.%20ALLEN%20(ST.%20ALLEYNE)%20CHURCHYARD

PRIVATE JOHN HENRY TREMAIN

Service Number: 22759

Regiment & Unit/Ship: Duke of Cornwall's Light Infantry 12th Bn.

Date of Death: Died 28 May 1916   Age 31 years 

Country of Service: United Kingdom

Additional Information:

Son of William Tremain, of Zelah, Callestick; husband of Edith Godfrey (formerly Tremain), of 3, Tregurra Lane, Truro.