Lieutenant Colonel Harry Arthur Smith, SG, MC (25 July 1933 – 20 August 2023) was a senior officer in the Australian Army, seeing service during the Malayan Emergency and the Vietnam War.

[4][2] After service as a National Serviceman, Smith joined the Australian Regular Army and graduated as second lieutenant from the Officer Cadet School, Portsea.

On 18 August, after heavy mortar shelling of the Australian base at Nui Dat the previous night, companies from 6 RAR were sent out to locate the Vietnamese units involved.

Smith led the 105 soldiers of D Coy and the 3 man NZ Artillery Party out on patrol, but at 3:15 pm, while patrolling a rubber plantation at Long Tan that afternoon, they encountered a reinforced regiment-sized Vietnamese force (the Viet Cong 275th Regiment, supported by the North Vietnamese Army 806 Battalion and D440 and D445 Battalions) attempting to advance on the base.

[10] On 14 August 2008, after years of campaigning for better recognition of Long Tan veterans, Smith's Military Cross was upgraded to the Star of Gallantry[2] (the Australian honours system replacement for the Commonwealth Distinguished Service Order).