Lieutenant General Sir Leonard Whitmore Thornton, KCB, CBE (15 October 1916 – 10 June 1999) was a senior officer in the New Zealand Army. Born in Christchurch, Thornton joined the Royal New Zealand Artillery in 1937 after having been encouraged by his uncle, Leonard Isitt, to pursue a military career. He served throughout the Second World War in a number of artillery and staff posts. Shortly after the war, he was appointed the commander of the artillery of the 2nd New Zealand Division. After holding a series of senior posts in the New Zealand Army, including a period as its commander, he was appointed Chief of the Defence Staff in 1965 for a six-year term. Knighted in 1967, he was later the New Zealand ambassador to the Republic of Vietnam. He died in 1999 at the age of 82.