Lieutenant-General Sir Walter Sinclair Delamain KCB KCMG DSO (18 February 1862 – 6 March 1932) was an officer of the British Indian Army.

He attended the Royal Military College and was commissioned as a lieutenant in the Princess Charlotte of Wales's (Berkshire Regiment) on 22 October 1881.

[9] On 26 May 1901 he was appointed a Special Service Officer on the staff of the China Field Force,[10] and his rank of major was made substantive on 10 July 1901.

[20] His conduct was described as "admirable" in General Nixon's despatch,[21] and Delamain was promoted to major-general, 29 October 1915, for distinguished service in the field.

[23] On 14 November 1919 Delamain was given command of a division,[24] and he was promoted to lieutenant-general on 1 April 1920,[25] with seniority later backdated to 21 December 1919.