158th Brigade, Royal Field Artillery, (Accrington and Burnley Howitzers).

Awarded the Military Medal in the London Gazette of 21 October 1916.

Riley was a native of Burnley, Lancashire.

The Burnley Express of 4 November 1916 reported: - BURNLEY WIDOW'S MEDAL. HONOUR FOR DEAD SERGEANT. The first Military Medal awarded to the relatives of a dead Burnley soldier has been bestowed on Mrs. Riley, of 23, Haslam Street, widow of the late Sergeant Harold Riley, of the Burnley Howitzers. Sergenat Riley, who was 27 years of age and the son of Mr. and Mrs. Riley of 15, Devonshire Street, Burnley. About eighteen months before the Howitzers was formed he married Rachael Layfield of Haslam Street where she is now living with her mother. Before enlisting he was employed as an assistant grocer by Messrs. Metcalfe of St. James' Street, and was very well known and liked by many around the town. He was a member of the V.T.C., before joining the army and was always a smart young man.

Sergeant Riley was struck in the eye by a peice of shrapnel on the 28 July 1916, he diied of wounds on the 29 July 1916 in hospital at Rouen, France. Buried in St. Sever Cemetery, Rouen, France.