Clive Vallack Single, D.S.O., M.B.,[a] (17 September 1888 – 10 July 1931) was an Australian cricketer,[1] baseballer, soldier, and medical practitioner.

He played two first-class matches for New South Wales in 1912,[2] and three interstate baseball matches for New South Wales in 1911; and, having enlisted in December 1914, he served as a medical officer in the First AIF, in the Middle East, eventually reaching the rank of lieutenant-colonel — he was awarded a D.S.O.

[28][29][30] A talented cricketer with both bat and ball,[31] he played in two Sheffield Shield matches for New South Wales, against Western Australia in November 1912.

[32][33] Following his graduation from university, and prior to his enlistment in December 1914, he played for Glebe Cricket Club in the 1913/1914 and 1914/1915 seasons.

On 23 March 1918, he was promoted to lieutenant-colonel, and placed in charge of the 4th Australian Light Horse Field Ambulance and served there, in Egypt, until he was demobilized in 1919.